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Review

Novel Nanomaterials for Hydrogen Production and Storage: Evaluating the Futurity of Graphene/Graphene Composites in Hydrogen Energy

by
Ahmed Hussain Jawhari
Department of Chemistry, Faculty of Science, Jazan University, P.O. Box 2097, Jazan 45142, Saudi Arabia
Energies 2022, 15(23), 9085; https://doi.org/10.3390/en15239085
Submission received: 15 October 2022 / Revised: 3 November 2022 / Accepted: 17 November 2022 / Published: 30 November 2022
(This article belongs to the Special Issue Applications of Nanomaterials in Clean Energy)
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Abstract

:
Using hydrogen energy as an alternative renewable source of fuel is no longer an unrealized dream, it now has real-world application. The influence of nanomaterials on various aspects of hydrogen energy, such as hydrogen production, storage, and safety, is considerable. In this review, we present a brief overview of the nanomaterials that have been used as photocatalysts during hydrogen production. The use of nanomaterials and nanomaterial composites for hydrogen storage is also reviewed. The specific use of graphene and its associated nanocomposites, as well as the milestones reached through its application are elaborated. The need to widen the applicability of graphene and its allied forms for hydrogen energy applications is stressed in the future perspectives. Hydrogen energy is our future hope as an alternative renewable fuel, and graphene has the potential to become the future of hydrogen energy generation.

1. Introduction

Based on current consumption statistics, it is estimated that energy supplies from fossil fuels, such as coal, natural gas, and oil, will last up to 50, 53, and 114 years, respectively [1]. Nevertheless, the continuous exploitation of fossil fuels will bring about a negative environmental impact through enormous CO2 emissions, which in turn can worsen global warming and have other human health-related impacts [2]. The demand for oil, and concerns about the rising levels of atmospheric CO2 affecting climatic conditions, have resulted in a pressing need to transition from fossil fuels to hydrogen (H2) fuels. Hydrogen energy is an alternate clean energy acquired from renewable resources. Non-depleting energy resources with self-replenishing capacities will positively aid our chances of creating a sustainable future [3,4]. Renewable energy is obtained from tidal/wave energy, biomass energy, geothermal energy, wind energy, solar energy, hydropower, and other natural sources. Though much emphasis has been placed on adapting renewable resources for clean energy production, their availability is subject to regional and seasonal factors [5].
Hydrogen, which is an alternative energy carrier to generate electricity, is obtained by splitting water, a renewable resource, through a simple and straightforward process called electrolysis. This being the case, the production of hydrogen will directly depend on the availability of water on earth. It is a simple and clean technology that does not generate any toxic pollutants other than pure water as a byproduct. Moreover, the fact that hydrogen has a comparatively higher specific energy density than other hydrocarbons is a key advantage [6,7]. Furthermore, hydrogen production can also be enabled by a wide variety of raw materials, including oil, gas, biofuels and sewage sludge [8], which make it easy to be locally produced without depending on external energy suppliers to ensure continuous production.
Hydrogen is produced using various techniques, such as steam methane reformation, hydrocarbon oxidation, coal gasification, and water–gas shift reaction, as well as from renewable sources, such as biomass and water, and water splitting techniques such as electrolysis, thermolysis, and photoelectrolysis via photocatalytic splitting are also being utilized. Figure 1 illustrates the process of the photocatalytic splitting of water for hydrogen production. However, for the hydrogen economy to be realized, many technical issues need to be resolved, of which discovering an ideal energy-efficient method for H2 storage within limited space is the most important [9].
Hydrogen storage promotes hydrogen production and applications, which make it very important for initiating the hydrogen economy [10,11,12,13]. In order to serve the requirements of fuel cell cars, onboard hydrogen storage is very important [14,15]. The optimal attributes that are prerequisites for hydrogen storage materials used in automobile applications include: (i) lightweight, (ii) cost-effective and readily available, (iii) high volumetric/gravimetric hydrogen density, (iv) rapid kinetics, (v) easily available for activation, (vi) low dissociation or decomposition temperature, (vii) ideal thermodynamic properties, (viii) extended cycling, and (ix) optimal degree of reversibility. These traits aid in understanding the fundamental mechanisms behind hydrogen catalysts and their physicochemical interactions with hydrogen at atomic or molecular scales.
Currently, metal, complex and chemical hydrides, adsorbents, nanospheres, nanotubes, nanofibers, nanohorns, nanoparticles, polymer nanocomposites, metal–organic frameworks, clathrate hydrates, and other materials [16,17,18,19,20,21] have been considered as candidate materials for hydrogen storage. However, none of these are able to deliver the adequate requirements, which include: (1) high hydrogen content (>6.0 wt.%), (2) favorable or tunable thermodynamics (30–55 kJ/mol H2), (3) operation below 100 °C for H2 delivery, (4) onboard refueling, and (5) cyclic reversibility (∼1000 cycles) at moderate temperatures.
Nanotechnology is the fundamental understanding of physics, chemistry, biology, and technology of nanometer-scale objects. Nanotechnology is devoted to manipulating atoms and molecules at nanoscale dimensions, for designing, producing, and innovating structures, devices, and systems. Nanomaterials are those with dimensions of the order of 100 nanometers (100 millionth of a millimeter or less). Nanotechnology has successfully manipulated the molecular structure of materials, changing their intrinsic properties and obtaining others with revolutionary applications. Unique material reinforcements have been enabled based on nanotechnological inputs. Transparent graphene-modified carbon harder than steel, lighter than aluminum, has been fabricated. Various other technological marvels have been enabled using nanotechnology, enriching electronics, energy, biomedicine, and defense applications [22,23].
In the following review, we survey the various nanomaterials that have been used for hydrogen production and hydrogen storage. The novel next-generation nanocomposites that have been used for hydrogen production, especially as photocatalysts, are discussed, and those aspects of carbon nanomaterials which have been less explored are identified as future projections.

2. Nanomaterials Used in Hydrogen Production

Hydrogen production involves four different methods: (1) photoelectrochemical (PEC) water splitting, (2) solid-state hydrogen storage, (3) photocatalytic hydrogen production, and (4) proton exchange membrane fuel cells (PEMFCs). Photocatalysis involves the following reaction: photogenerated electrons and holes at the conduction and valence bands lead to the redox reaction, resulting in hydrogen and oxygen production. Efficient photocatalysts are expected to possess: (1) suitable band gaps and structures to absorb sunlight/UV light, leading to hydrogen- and oxygen-evolution half-reactions; (2) good charge transfer ability for electrons and holes, with low recombination rates; and (3) high surface area for catalytic activity. Fujishima and Honda first reported the successful use of TiO2 anode and Pt cathode for solar-driven water splitting for hydrogen production [24]. In 1979, Bard designed a water splitting system that operates photocatalytically, using particles/powders as semiconductor photocatalysts [25]. PEC water splitting is considered the primary approach and TiO2 is the best choice of semiconductor for PEC water splitting [26,27]. TiO2 band gap is 3.2 eV, hence it is difficult to absorb visible and infrared light for solar water splitting, this is why metal or non-metal ion doping has been involved in narrowing down the band gap of TiO2, so that TiO2 is also functional under visible light [26,28]. C-doped TiO2 nanocrystalline films possess high water splitting performance with enhanced conversion efficiency (11%) and photoconversion efficiency (8.35%), besides these credentials, they were active under visible light, which was an added advantage [29]. Grimes et al. demonstrated TiO2 nanotube arrays for PEC water splitting yielding a photoconversion efficiency of 16.5% under UV light. The nanotube system owing to its nanotubular architecture, achieves superior electron lifetime and enhanced charge separation [30,31,32,33,34,35,36]. TiO2 and fluorine-doped tin dioxide (SnO2:F, and FTO), which is commonly used for preparing transparent conductive oxides (TCO), has been reported for their contribution in PEC cells [37]. ZnO is yet another popular wide band gap semiconductor, predominantly used for PEC water splitting applications [38,39]. Ion doping [40,41,42] and visible light sensitization with narrow band gap semiconductors [43,44,45] have expanded the light absorption range and improved the performance of PEC. ZnO nanostructures were doped with shallow Al donor levels, with added Ni for improved optical absorption [46]. Oval core/shell α-Fe2O3 nanorod nanoarrays, modified with thin WO3/TiO2 overlayers, have been reported to result in enhanced photo efficacy [47]. Other authors controllably tuned the ZnIn2S4 microstructure for enhanced visible light-mediated hydrogen evolution [48,49,50]. In the past decades, innumerable reports have addressed the critical requirements of photocatalysts [28,51,52,53,54,55].
Nanomaterials such as CdS, SiC, CuInSe2, and TiO2 have been used for photocatalytic hydrogen production [27,56,57,58] and demonstrated for their enhanced photocatalytic properties. Currently, Nb2O5 [59], Ta2O5 [60], α-Fe2O3 [61,62], ZnO [38,39], TaON [63], BiVO4 [64,65], and WO3 nanomaterials have been explored [66]. In most of these, band gap limitation can lower H2 production [67]. To resolve this issue, noble metal/ion doping, sensitization and metal ion implantation techniques have been attempted. In noble metal doping, Pt is the best; but it is extremely expensive, so Ag, Ru, Pd, Ni, Cu, and Ir have been explored in parallel [68,69,70,71,72,73,74,75,76]. Incorporation of co-catalysts with photocatalyst nanomaterials for photocatalytic hydrogen production has also been attempted.
Loading cocatalysts onto photocatalysts to lead to hydrogen or oxygen evolution sites has enhanced photocatalytic splitting of water. In the past, transition metals, metal oxides, metal sulfides and noble metals, such as Pt, Ru, Au, and metal oxides, such as NiOx, Rh/Cr2O3, etc., were well utilized as water reduction cocatalysts by entrapping electrons [28,52]. IrO2, RuO2, Rh2O3, Co3O4, and Mn3O4 metal oxides have been able to function as effective oxidation cocatalysts by entrapping the holes [51]. Researchers have loaded noble metals and metal sulfides as dual cocatalysts (Pt–Ag2S and Pt–CuS), which could result in efficient separation of photogenerated electrons and holes for enhanced hydrogen evolution [77,78].

3. Nanomaterials Used in Hydrogen Storage

Various hydrogen storage systems have been explored for hydrogen storage applications [16,17,18,19,20,21,79,80,81]. These include metal hydrides, complex hydrides, chemical hydrides, adsorbents and nanomaterials (nanotubes, nanofibers nanohorns, nanospheres, and nanoparticles), clathrate hydrates, polymer nanocomposites, metal organic frameworks, and others [9,16,17,18,19,20,21,81,82,83]. However, as mentioned earlier, none of the currently available materials meet all these requirements, and the hydrogen content, release temperature and reversibility requirements are especially hard to meet. The other major option is solid-state hydrogen storage in light metal hydrides [10,12,13,14,84,85,86] and complex hydrides such as alanates [87,88], amides [89,90], borohydrides [90,91,92] and their combinations [93,94]. An offset of light metal hydrides are the alkali/alkali earth metal hydrides NaH, LiH, and MgH2. Interstitial, or metallic, hydrides such as PdHx are formed by transition and rare earth elements. Covalently bound hydrides such as AlH3 and NH3BH3 are also used, but have their own limitations. Recently, the focus has been more on boron hydrides such as LiBH4, alanates such as NaAlH4, and even systems containing multiple phases, such as LiBH4+MgH2. Yet, most of these store 5 wt.% hydrogen and face kinetics and reversibility issues because of its complex nature and the presence of multiple phases after dehydrogenation. This being the case, the other alternative method of increasing the hydrogen sorption kinetics is nanostructuring. Stable crystallites of 5–10 nm were reported in a MgH2TiH2 system [95], smaller particles with sizes less than 10 nm have also been used. In 2005, the breakthrough pioneering work on nanoconfined borane in mesoporous silica enabled major changes in their hydrogen desorption properties, paving the way for a new beginning [96]. Additional effects have been identified, such as better mechanical stability and thermal management during cycling via incorporating carbon materials [97,98,99].
Carbonaceous materials are an attractive option for hydrogen storage owing to its adsorption ability, high specific surface area, pore microstructure, and low mass density. Despite numerous reports on hydrogen uptake by carbon materials, the actual mechanism of storage remains a mystery. The interaction is possibly based on van der Waals attractive forces (physisorption) or by chemisorption. The physisorption of hydrogen, limits the hydrogen-to-carbon ratio restricted to less than one hydrogen atom per two carbon atoms (i.e., 4.2 mass %). In chemisorption, this is realized as in the case of polyethylene [100,101,102]. Dillon et al. presented the first report on hydrogen storage in carbon nanotubes [103], which activated ripples worldwide in carbonaceous materials research. Now, it is known that hydrogen can be physically adsorbed on activated carbon and be “packed” more densely on the surface and inside the structure of carbon, as if it is compressed. The best results using carbon nanotubes, are verified to correspond to a hydrogen storage density of about 10% of the nanotube weight [104].
Fullerenes are currently one of the most popular carbon allotrophs with a close-caged molecular structure [105]. They are able to react with hydrogen via the hydrogenation of carbon–carbon double bonds and so have been used for hydrogen storage. A maximum number of nearly 60 hydrogen atoms can be attached inside (endohedrally) and outside (exothermally) the spherical fullerene surfaces. Thus, a stable C60H60 isomer is obtained with a theoretical hydrogen content of ∼7.7 wt.%. It seems that the fullerene hydride reaction is reversible at high temperatures. The 100% conversion of C60H60 indicates that 30 moles of H2 gas will be released from each mole of fullerene hydride compound, but this reaction requires high temperatures ranging from 823–873 K [106,107].
Hydrogen can also be stored in glass microspheres of approximately 50 μm diameter. These microspheres can be loaded with H2 through heating these glass microspheres to increase their permeability to hydrogen. A pressure of approximately 25 MPa, resulting in a storage density of 14% mass fraction and 10 kg H2/m3 is reported [106]. At 62 MPa, a bed of glass microspheres can store 20 kg H2/m3. The release of hydrogen is through reheating the spheres, which increases the permeability of hydrogen. Carbon-based sorbents, synthesized from various organic precursors, can be structured into various carbon forms, such as carbon nanotubes [108,109,110], fibers [108,110], fullerenes [110,111], and activated carbons [112,113]. These structurally diverse forms can be tuned for hydrogen gas storage. Metal–organic frameworks (MOFs) are highly porous, crystalline solids consisting of a periodic array of metal clusters linked through multi-topic organic struts [114,115]. Other highly porous, crystalline materials include zeolitic imidazolate frameworks (ZIFs) [116] and covalent organic frameworks (COFs) [117], which have also been considered as an option for hydrogen storage.
Nanocomposites consist of a polyaniline matrix that can be functionalized by catalytic doping or incorporation of a nanovariant. It has been reported that polyaniline can store 6–8 wt.% of hydrogen [118] and a recent study revealed a successful hydrogen uptake of 1.4–1.7 wt.% [119]. With all this in mind, there is still an urgent need for the development of new reversible materials. Clathrates are a new class of materials for hydrogen storage [18], which are primarily hydrogen-bonded H2O frameworks, where hydrogen molecules can be incorporated, making it useful for off-board storage of hydrogen.

4. Graphene-Based Nanocomposites for Hydrogen Energy Applications

Carbon materials such as carbon nanodots, fullerenes, graphene, CQDs, (C60), and carbon nanotubes (CNTs) have been applied for surface modification of photocatalysts for hydrogen production [120]. Carbon materials have been used for enhancing hydrogen production at all ranges of the optical spectra. The results have shown that the use of carbon materials has extended the visible-light absorption range and enabled higher charge transfer. Graphene exhibits higher charge carrier mobility, larger surface area, excellent electrical and thermal conductivity, as well as good physical and chemical stability, moreover, it is synthesized easily [121,122,123,124,125]. Zhang et al. reported enhanced photocatalytic H2 evolution from water splitting using graphene/Ti nanocomposites [126]. Li et al. prepared S and N co-doped graphene quantum dots/TiO2 (S,N-GQD/TiO2) composites for enabling efficient photocatalytic H2 evolution, it was also observed that these graphene-based nanocomposites exhibited higher photocatalytic activity than pure TiO2. This is owing to enhanced absorption of visible light and efficient separation and migration of electrons and holes [127]. Fan et al. reported TiO2/RGO nanocomposites [128], while Hao et al. anchored TiO2 with graphene quantum dots and reported enhanced photocatalytic H2 evolution [129], which is due to the credentials of graphene quantum dots that can act as efficient electron reservoirs and photosensitizers when associated with TiO2.
Of the carbon materials, graphene is most suitable hydrogen storage material because of its active surface area and superior chemical properties. It is used as a free metal catalyst owing to its favorable electrochemical and chemical properties. Its physico-chemical properties include high carrier mobility, elasticity and generous thermal conductivity [130]. The hybridization of graphene is sp2, its honeycomb-like structure accommodates the hydrogen atoms [131]. The adsorption is through either physisorption or chemisorption. Masjedi-Arani et al. [132] reported the synthesis and use of novel Cd2SiO4/graphene nanocomposites. Cd2SiO4 nanoparticles were blended into a graphene sheet to form Cd2SiO4/graphene nanocomposites. The electrochemical hydrogen storage capacity of Cd nanoparticles was found to be 1300 mA hg−1, which is nearly half of the storage capacity of Cd2SiO4/graphene nanocomposites (3300 mA hg−1). This is because of their ideal electrical properties and high surface area, which makes them more suitable for electrochemical hydrogen storage than graphene. Graphene is a highly lightweight material, so it is highly attractive for H-storage applications. Ngqalakwezi et al. prepared graphene nanocomposites through a modified Tours method [133]. Hydrogen uptake improved by 2% in graphene to 4.98 wt.% and 3.99 wt.% in calcium/graphene nanocomposites, respectively. The addition of ammonia increases hydrogen storage in graphene. Their group reported that the addition of magnesium onto reduced graphene oxide resulted in reduced graphene oxide–Mg composites [134] suitable for electrochemical hydrogen storage. These magnesium nanocrystals reinforced with fine and reduced graphene oxide sheets have been applied successfully for hydrogen storage (6.5 wt.% and 0.105 kg hydrogen per liter in the total composite). Ravi and Grace fabricated novel MnFe2O4/graphene and ZnFe2O4/graphene nanocomposites for hydrogen evolution [135].
Metal decorated Ni/graphene-like materials (GLM) are another class of nanocomposites [136] that have been reported for hydrogen applications. ZnAl2O4/graphene nanocomposites [137] were prepared by green synthesis using green tea and olive leaf extracts and applied for electrochemical hydrogen storage. ZnAl2O4/graphene and ZnAl2O4 nanocomposites yielded the highest coulombic efficiency (67.5%) and discharge capacity (3100 mAh g−1), respectively. Hierarchically prepared porous 3D-graphene materials were doped with TiO2 through the electrostatic assembly method and tested for hydrogen adsorption efficiency [138]. Porous graphene-TiO2 nanocomposites with greater pore volume (0.41 cm3 g−1) and high surface area (705 m2 g−1) and maximum storage capacity exhibited enhanced storage properties. In another study, vanadium-supported reduced graphene oxide nanocomposites combined with Mg85Al15 alloy were reported for hydrogen storage applications. Pd/graphene nanocomposites (8.67 wt.% in the 1% Pd/graphene nanocomposite with a pressure of 60 bar, and 7.16 wt.% uptake capacity) were also reported for enhanced H2 storage [139]. These are a few selective examples of nanocomposites contributing towards hydrogen storage. Jain and Kandasubramanian have recently reviewed the role of functionalized graphene in hydrogen energy storage [140]. Table 1 presents a consolidated list of the graphene/graphene composites that have been engaged in hydrogen storage applications.

5. Future Perspectives

With developing concerns regarding atmospheric changes and the consumption of non-sustainable power sources, a visualized hydrogen economy is a definite option. In this review, different solid-state H2 storage carbon-based nanomaterials were discussed. To accomplish H2 economy, storage is the crucial factor, as traditional storage systems cannot perform adequately on several onboard applications. To address the concerns for future fuel needs, hydrogen must be utilized correctly and efficient storage systems must be planned.
This article discussed numerous nanomaterials and their nanocomposites as potential options for hydrogen storage. The limitations of the existing options have been addressed, and it is anticipated that additions of the new-generation nanomaterials for solid-state H2 storage will be required to add to the future hydrogen vision.
We evaluated the current standing of hydrogen-energy-related nanomaterial research through a PubMed search. Nanomaterial contributions towards hydrogen production yielded a PubMed search result of 4264 hits (Figure 2a). Of these 4264 hits, 1161 hits (Figure 2b) resulted from the keywords ‘carbon nanomaterials and hydrogen production’, and 1468 hits from a keyword search for ‘hydrogen production and graphene’ (Figure 2c). Figure 3 clearly portrays the fact that, with respect to hydrogen storage, the PubMed search on ‘hydrogen storage and nanomaterials’ yielded 893 hits (Figure 3a), while, ‘hydrogen storage and carbon nanomaterials’ yielded 335 results (Figure 3b), and ‘hydrogen storage and graphene’ yielded 489 hits (Figure 3c). This PubMed based survey clearly reveals that in the current standing, carbon materials play a major role in hydrogen energy applications, be it hydrogen production or hydrogen storage. Furthermore, within the carbon nanomaterial itself, graphene and its nanocomposites hold a high reputation for their inputs towards hydrogen production and storage applications.
Hydrogen will apparently become the synthetic fuel for a hydrogen-based environmentally clean energy economy. Hydrogen storage needs to be planned to meet mobile or stationary storage requirements. Today, we know of several efficient and safe ways to produce and store hydrogen; we have reviewed the various nanomaterial options that have been applied towards hydrogen production and storage. The material science challenge is to develop a clearer understanding of the electronic behavior during the interaction between hydrogen and other elements, especially metals. Nanotechnology has been the source of numerous technical breakthroughs, the inputs of nanomaterials when put to use as photocatalysts and as storage materials have indeed helped overcome various barriers, however, there are many other new potential nanomaterials. Complex nanocomposite materials need to be explored for hydrogen production and storage options. Complex compounds such as Al(BH4)3 have to be investigated and new compounds from the lightweight metals need to be discovered. Particularly with respect to automobile applications, lightweight carriers are optimal. In this direction, energy conversion devices more efficient than the internal combustion engine, e.g., fuel cells, will be developed and will reduce the amount of hydrogen necessary on board and therefore also the weight of the storage system. In terms of light weight and utility, graphene is a prospective material. “Pristine” graphene is only one atomic layer thick, a material that has 10 atomic layers of carbon or fewer is referred to as graphene. Graphene is typically categorized based on its layers, as very-few-layered graphene (vFLG, 1–3 layers of carbon), few-layered graphene (FLG, 2–5 layers), multi-layer graphene (MLG, 2–10 layers), or graphene nanoplatelets (GNP, stacks of graphene sheets that consist of multiple layers and lateral dimensions ranging from 100 nanometers to 100 microns). Besides these, graphene is available commercially as graphene oxide (GO) and reduced graphene oxide (rGO), graphene powder, solution or paste and functionalized graphene. In this review, we presented scattered applications of graphene, mostly related to graphene nanocomposites, and we found that little has been done to test the utility of the other forms of graphene/GO, reduced GOs and their allies. Pristine and functionalized graphene have proven their unique applicability in numerous applications, but there is definitely more to offer.
Moreover, a clear understanding of the mechanism of hydrogen adsorption is very important in order to plan for designing the most appropriate nanocomposites that will cater to the storage mandate. It is known that the adsorption energy for the hydrogen molecule in a given material depends not only on the material nature but also on the hydrogen molecule’s interaction with the adsorption sites. Given this fact, Reguera (2009) [156] has elaborately discussed the five different interactions that contribute to the adsorption of H2, which include: quadrupole moment interaction with the local electric field gradient; electron cloud polarization by a charge center; dispersive forces (van der Waals); quadrupole moment versus quadrupole moment between neighboring H2 molecules, and H2 coordination to a metal center [157,158,159]. The relative importance of these five interactions in hydrogen storage has been comprehensively discussed in that review, to yield a clear understanding of designing the right material and combining the right materials for hydrogen storage. In most of the reports that design nanocomposites for hydrogen storage, this aspect is not addressed, but this review emphasizes that a clear understanding of this subject will lead to more promising and applicable nanocomposites.
Hydrogen storage has been well researched and widely supported by various publication records [160,161], the use of nanomaterials for hydrogen production and storage is also substantiated by various research records, however, this review highlighted the fact that there are many nanomaterials that have not been attempted. Specifically in terms of carbonaceous nanomaterials, there is a lot to be tapped. Graphene in particular has a lot to offer, and while there are reports, there is more to exploit. Additionally, the combination of materials, such as nanocomposites, has been a fruitful field, and nanocomposites have been utilized in terms of hydrogen systems, but more diverse nanocomposites, specifically combining carbon materials with other metallic nanomaterials, could also have a lot to offer. These are a few aspects that can take things forward more smoothly and rapidly, which this review highlights as prospects for future directions.
Although the demand for hydrogen fuel is increasing rapidly for automated application, the safety of high-capacity hydrogen storage remains a scientific challenge [134]. Safety is an important aspect that needs to be assessed and enhanced. Every technology has its pros and cons, working on the cons is a crucial direction. Safe hydrogen storage is an aspect to which nanomaterials have a lot to contribute, this is something that has not been prevalently worked on and disclosed. This is a future direction that could plausibly add to the knowledge and practical implications in this research area.

6. Concluding Remarks

The use of nanomaterials for hydrogen production and hydrogen storage applications were briefly reviewed. The use of carbonaceous nanomaterials for hydrogen energy applications were also reviewed, specifically the use of graphene and its allied forms for hydrogen energy applications. The dearth in widespread use of graphene and its associated forms for hydrogen storage applications have been discussed and its future prospects have been presented.

Funding

This research received no external funding.

Conflicts of Interest

The authors declare no conflict of interest.

References

  1. Dudley, B. BP Statistical Review of World Energy; BP Statistical Review: London, UK, 2018; p. 00116. [Google Scholar]
  2. D’Amato, M.; Cecchi, L.; Annesi-Maesano, I. Climate change and respiratory diseases. Eur. Respir. Rev. 2014, 23, 161–169. [Google Scholar] [CrossRef] [PubMed]
  3. Abbasi, T.; Abbasi, S.A. Renewable Energy Sources: Their Impact on Global Warming and Pollution; PHI Learning Pvt. Ltd.: Delhi, India, 2011. [Google Scholar]
  4. Kaygusuz, K. Energy for sustainable development: A case of developing countries. Renew. Sustain. Energy Rev. 2012, 16, 1116–1126. [Google Scholar] [CrossRef]
  5. Song, J.; Wei, C.; Huang, Z.-F.; Liu, C.; Zeng, L.; Wang, X.; Xu, Z. A review on fundamentals for designing oxygen evolution electrocatalysts. J. Chem. Soc. Rev. 2020, 49, 2196–2214. [Google Scholar] [CrossRef] [PubMed]
  6. Safari, F.; Dincer, I. A review and comparative evaluation of thermochemical water splitting cycles for hydrogen production. Energy Convers. Manag. 2020, 205, 112182. [Google Scholar] [CrossRef]
  7. Nicoletti, G.; Arcuri, N.; Nicoletti, G.; Bruno, R. A technical and environmental comparison between hydrogen and some fossil fuels. Energy Convers. Manag. 2015, 89, 205–213. [Google Scholar] [CrossRef]
  8. Revankar, S.T. Chapter four-nuclear hydrogen production. In Storage and Hybridization of Nuclear Energy; Bindra, H., Revankar, S., Eds.; Academic Press: Cambridge, MA, USA, 2019; pp. 49–117. [Google Scholar]
  9. Schlapbach, L.; Züttel, A. Hydrogen-storage materials for mobile applications. Nature 2001, 414, 353–358. [Google Scholar] [CrossRef]
  10. Jones, R.H.; Thomas, G.J. Materials for the Hydrogen Economy; CRC Press: Boca Raton, FL, USA, 2007; Catalog no.5024. [Google Scholar]
  11. Basic Research Needs for hydrogen Economy. In Report on the Basic Energy Sciences Workshop on Hydrogen Production, Storage, and Use; Argonne National Laboratory: Lemont, IL, USA, 2003. Available online: https://www.hydrogen.energy.gov/pdfs/nhe_rpt.pdf (accessed on 14 October 2022).
  12. Schlapbach, L. Hydrogen as a fuel and its storage for mobilityand transport. MRS Bull. 2002, 27, 675–676. [Google Scholar] [CrossRef] [Green Version]
  13. Read, C.; Thomas, G.; Ordaz, C.; Satyapal, S.U.S. Department of Energy’s system targets for on-board vehicular hydrogen storage. Mater. Matters 2007, 2, 3. [Google Scholar]
  14. Züttel, A. Materials for hydrogen storage. Mater. Today 2003, 6, 24–33. [Google Scholar] [CrossRef]
  15. Chandra, D.; Reilly, J.J.; Chellappa, R. Metal hydrides for vehicular applications: The state of the art. JOM 2006, 58, 26–32. [Google Scholar] [CrossRef]
  16. Seayad, A.M.; Antonell, D.M. Recent advances in hydro gen storage in metal-containing inorganic nanostructures and related materials. Adv. Mater. 2004, 16, 765–777. [Google Scholar] [CrossRef]
  17. Pinkerton, F.E.; Wicke, B.G. Bottling the hydrogen genie. Ind. Phys. 2004, 10, 20–23. [Google Scholar]
  18. Schuth, F. Technology: Hydrogen and hydrates. Nature 2005, 434, 712–713. [Google Scholar] [CrossRef]
  19. Schüth, F.; Bogdanović, B.; Felderhoff, M. Light metal hydrides and complex hydrides for hydrogen storage. Chem. Commun. 2004, 10, 2249–2258. [Google Scholar] [CrossRef]
  20. McKeown, N.B.; Makhseed, S.; Msayib, K.J.; Ooi, L.-L.; Helliwell, M.; Warren, J.E. A phthalocyanine clathrate of cubic symmetry containing interconnected solvent-filled voids of nanometer dimensions. Angew. Chem. Int. 2005, 44, 7546–7549. [Google Scholar] [CrossRef]
  21. Fichtner, M. Nanotechnological aspects in materials for hydrogen storage. Adv. Eng. Mater. 2005, 7, 443–455. [Google Scholar] [CrossRef]
  22. Sahoo, M.; Panigrahi, C.; Vishwakarma, S.; Kumar, J. A Review on Nanotechnology: Applications in Food Industry, Future Opportunities, Challenges and Potential Risks. J. Nanotechnol. Nanomater. 2022, 3, 28–33. [Google Scholar] [CrossRef]
  23. Singh, T.; Shukla, S.; Kumar, P.; Wahla, V.; Bajpai, V.K.; Rather, I.A. Application of Nanotechnology in Food Science: Perception and Overview. Front. Microbiol. 2017, 8, 1501. [Google Scholar] [CrossRef] [Green Version]
  24. Fujishima, A.; Honda, K. Electrochemical photolysis of water at asemiconductor electrode. Nature 1972, 238, 37–38. [Google Scholar] [CrossRef]
  25. Bard, A.J. Photoelectrochemistry and heterogeneous photo-catalysis at semiconductors. J. Photochem. 1979, 10, 59–75. [Google Scholar] [CrossRef]
  26. Chen, X.; Mao, S.S. Titanium dioxide nanomaterials: Synthesis, properties, modifications, and applications. Chem. Rev. 2007, 107, 2891–2959. [Google Scholar] [CrossRef] [PubMed]
  27. Ni, M.; Leung, M.K.H.; Leung, D.Y.C.; Sumathy, K. A review andrecent developments in photocatalytic water-splitting using TiO2 for hydrogen production. Renew. Sustain. Energy Rev. 2007, 11, 401–425. [Google Scholar] [CrossRef]
  28. Chen, X.; Shen, S.; Guo, L.; Mao, S.S. Semiconductor-based photocatalytic hydrogen generation. Chem. Rev. 2010, 110, 6503–6570. [Google Scholar] [CrossRef]
  29. Khan, S.U.M.; Al-Shahry, M.; Ingler, W.B., Jr. Efficient photochemical water splitting by a chemically modified n-TiO2. Science 2002, 297, 2243–2245. [Google Scholar] [CrossRef] [PubMed]
  30. Rani, S.; Roy, S.C.; Paulose, M.; Varghese, O.K.; Mor, G.K.; Kim, S.; Yoriya, S.; LaTempa, T.J.; Grimes, C.A. Synthesis and applicationsof electrochemically self-assembled titania nanotube arrays. Phys. Chem. Chem. Phys. 2010, 12, 2780–2800. [Google Scholar] [CrossRef]
  31. Mor, G.K.; Prakasam, H.E.; Varghese, O.K.; Shankar, K.; Grimes, C.A. Vertically oriented Ti–Fe–O nanotube array films:toward a useful material architecture for solar spectrum waterphotoelectrolysis. Nano Lett. 2007, 7, 2356–2364. [Google Scholar] [CrossRef]
  32. Mor, G.K.; Shankar, K.; Paulose, M.; Varghese, O.K.; Grimes, C.A. Enhanced photocleavage of water using titania nanotubearrays. Nano Lett. 2005, 5, 191–195. [Google Scholar] [CrossRef]
  33. Varghese, O.K.; Paulose, M.; Shankar, K.; Mor, G.K.; Grimes, C.A. Water-photolysis properties of micron-length highly-ordered titaniananotube-arrays. J. Nanosci. Nanotechnol. 2005, 5, 1158–1165. [Google Scholar] [CrossRef]
  34. Shankar, K.; Mor, G.K.; Prakasam, H.E.; Yoriya, S.; Paulose, M.; Varghese, O.K.; Grimes, C.A. Highly-ordered TiO2 nanotubearrays up to 220 mm in length: Use in water photoelectrolysis and dye-sensitized solar cells. Nanotechnology 2007, 18, 065707. [Google Scholar] [CrossRef]
  35. Paulose, M.; Shankar, K.; Yoriya, S.; Prakasam, H.E.; Varghese, O.K.; Mor, G.K.; Latempa, T.A.; Fitzgerald, A.; Grimes, C.A. Enhancedphotocleavage of water using titania nanotube arrays. J. Phys. Chem. B 2006, 110, 16179–16184. [Google Scholar] [CrossRef]
  36. Mor, G.K.; Varghese, O.K.; Wilke, R.H.T.; Sharma, S.; Shankar, K.; Latempa, T.J.; Choi, K.S.; Grimes, C.A. p-Type Cu-Ti-O nanotube arrays and their use in self-biased heterojunction photoelectrochemical diodes for hydrogen generation. Nano Lett. 2008, 8, 1906–1911. [Google Scholar] [CrossRef]
  37. Kronawitter, C.X.; Kapilashrami, M.; Bakke, J.R.; Bent, S.F.; Chuang, C.-H.; Pong, W.-F.; Guo, J.; Vayssieres, L.; Mao, S.S. TiO2–SnO2: F interfacial electronic structure investigated by softx-ray absorption spectroscopy. Phys. Rev. B 2012, 85, 125109. [Google Scholar] [CrossRef]
  38. Hochbaum, A.I.; Yang, P. Semiconductor nanowires for energyconversion. Chem. Rev. 2010, 110, 527–546. [Google Scholar] [CrossRef]
  39. Lin, Y.J.; Yuan, G.B.; Liu, R.; Zhou, S.; Sheehan, S.W.; Wang, D.W. Semiconductor nanostructure-based photoelectrochemical watersplitting: A brief review. Chem. Phys. Lett. 2011, 507, 209–215. [Google Scholar] [CrossRef]
  40. Yang, X.; Wolcott, A.; Wang, G.; Sobo, A.; Fitzmorris, R.C.; Qian, F.; Zhang, J.Z.; Li, Y. Nitrogen-doped ZnO nanowire arrays forphotoelectrochemical water splitting. Nano Lett. 2009, 9, 2331–2336. [Google Scholar] [CrossRef]
  41. Shet, S.; Ahn, K.S.; Nuggehalli, R.; Yan, Y.F.; Turner, J.; Al-Jassim, M. Phase separation in Ga and N co-incorporated ZnO films and itseffects on photo-response in photoelectrochemical water splitting. Thin Solid Film. 2011, 519, 5983–5987. [Google Scholar] [CrossRef]
  42. Yousefi, M.; Amiri, M.; Azimirad, R.; Moshfegh, A.Z. Enhanced photoelectrochemical activity of Ce doped ZnO nanocomposite thin films under visible light. J. Electroanal. Chem. 2011, 661, 106–112. [Google Scholar] [CrossRef]
  43. Kim, H.; Seol, M.; Lee, J.; Yong, K. Highly Efficient Photoelectrochemical Hydrogen Generation Using Hierarchical ZnO/WOx Nanowires Cosensitized with CdSe/CdS. J. Phys. Chem. C 2011, 115, 25429–25436. [Google Scholar] [CrossRef]
  44. Wang, G.; Yang, X.; Qian, F.; Zhang, J.Z.; Li, Y. Double-sided CdS and CdSe quantum dot co-sensitized ZnO nanowire arrays for photoelectrochemical hydrogen generation. Nano Lett. 2010, 10, 1088–1092. [Google Scholar] [CrossRef]
  45. Chouhan, N.; Yeh, C.L.; Hu, S.-F.; Liu, R.-S.; Chang, W.-S.; Chen, K.-H. Photocatalytic CdSe QDs-decorated ZnO nanotubes: Aneffective photoelectrode for splitting water. Chem. Commun. 2011, 47, 3493–3495. [Google Scholar] [CrossRef]
  46. Kronawitter, C.X.; Ma, Z.; Liu, D.; Mao, S.S.; Antoun, B.R. Engineering impurity distributions in photoelectrodes for solar water oxidation. Adv. Energy Mater. 2012, 2, 52–57. [Google Scholar] [CrossRef]
  47. Kronawitter, C.X.; Vayssieres, L.; Shen, S.; Guo, L.; Wheeler, D.A.; Zhang, J.Z.; Antoun, B.R.; Mao, S.S. A perspective on solar-driven water splitting with all-oxide hetero-nanostructures. Energy Environ. Sci. 2011, 4, 3889–3899. [Google Scholar] [CrossRef]
  48. Shen, S.; Zhao, L.; Guo, L. Morphology, structure and photocatalytic performance of ZnIn2S4 synthesized via a solvothermal/hydrothermal route in different solvents. J. Phys. Chem. Solids 2008, 69, 2426–2432. [Google Scholar] [CrossRef]
  49. Shen, S.; Zhao, L.; Guo, L. Cetyltrimethylammonium bromide (CTAB)-assisted hydrothermal synthesis of ZnIn2S4 as an efficient visible-light-driven photocatalyst for hydrogen production. Int. J. Hydrogen Energy 2008, 33, 4501–4510. [Google Scholar] [CrossRef]
  50. Shen, S.; Zhao, L.; Guo, L. Crystallite, optical and photocatalytic properties of visible-light-driven ZnIn2S4 photocatalysts synthesized via a surfactant-assisted hydrothermal method. Mater. Res. Bull. 2009, 44, 100–105. [Google Scholar] [CrossRef]
  51. Shen, S.; Mao, S.S. Nanostructure designs for effective solar to hydrogen conversion. Nanophotonics 2012, 1, 31–50. [Google Scholar] [CrossRef]
  52. Shen, S.; Shi, J.; Guo, P.; Guo, L. Visible-light-driven photocatalytic water splitting on nanostructured semiconducting materials. Int. J. Nanotechnol. 2011, 8, 523. [Google Scholar] [CrossRef]
  53. Osterloh, F.E. Inorganic materials as catalysts for photochemical splitting of water. Chem. Mater. 2008, 20, 35–54. [Google Scholar] [CrossRef]
  54. Kudo, A.; Miseki, Y. Heterogeneous photocatalyst materials for water splitting. Chem. Soc. Rev. 2009, 38, 253–278. [Google Scholar] [CrossRef]
  55. Maeda, K.; Domen, K. Photocatalytic water splitting: Recentprogress and future challenges. J. Phys. Chem. Lett. 2010, 1, 2655–2661. [Google Scholar] [CrossRef]
  56. Jang, J.W.; Kim, H.G.; Joshi, U.A.; Lee, J.S. Fabrication of CdS nanowires decorated with TiO2 nanoparticles for photocatalytic hydrogen production under visible light irradiation. Int. J. Hydrogen Energy 2008, 33, 5975–5980. [Google Scholar] [CrossRef]
  57. Sebastian, P.J.; Castaneda, R.; Ixtlilco, L.; Mejia, R.; Pantojaand, J.; Olea, A. Synthesis and characterization of nanostructured semiconductors for photovoltaic and photoelectrochemical cell applications. Proc. SPIE 2008, 7044, 704405. [Google Scholar] [CrossRef]
  58. Silva, L.A.; Ryu, S.Y.; Choi, J.; Choi, W.; Hoffmann, M.R. Photocatalytic Hydrogen Production with Visible Light over Pt-Interlinked Hybrid Composites of Cubic-Phase and Hexagonal-Phase CdS. J. Phys. Chem. C 2008, 112, 12069. [Google Scholar] [CrossRef]
  59. Chen, X.; Yu, T.; Fan, X.; Zhang, H.; Li, Z.; Ye, J.; Zou, Z.; Chen, X.; Yu, T.; Fan, X.; et al. Enhanced activity of mesoporous Nb2O5 for photocatalytic hydrogen production. Appl. Surf. Sci. 2007, 253, 8500. [Google Scholar] [CrossRef]
  60. Takahara, Y.; Konde, J.; Takata, N.T.; Lu, D.; Domen, K. Mesoporous tantalum oxide-characterization and photocatalytic activity for the overall water decomposition. Chem. Mater. 2001, 13, 1194. [Google Scholar] [CrossRef]
  61. Kim, J.Y.; Jang, J.W.; Youn, D.H.; Magesh, G.; Lee, J.S. A Stable and Efficient Hematite Photoanode in a Neutral Electrolyte for Solar Water Splitting: Towards Stability Engineering. Adv. Energy Mater. 2014, 4, 1400476. [Google Scholar] [CrossRef]
  62. Sivula, K.; Le Formal, F.; Grätzel, M. Solar Water Splitting: Progress Using Hematite (α-Fe2O3) Photoelectrodes. ChemSusChem 2011, 4, 432–449. [Google Scholar] [CrossRef]
  63. Hitoki, G.; Takata, T.; Kondo, J.N.; Hara, M.; Domen, H.K.K. An oxynitride, TaON, as an efficient water oxidation photocatalyst under visible light irradiation (λ ≤ 500 nm). Chem. Commun. 2002, 16, 1698–1699. [Google Scholar] [CrossRef]
  64. Kudo, A.; Ueda, K.; Kato, H.; Mikami, I. Photocatalytic O2 evolution under visible light irradiation on BiVO4 in aqueous AgNO3 solution. Catal. Lett. 1998, 53, 229–230. [Google Scholar] [CrossRef]
  65. Kudo, A.; Omori, K.; Kato, H.J. A Novel Aqueous Process for Preparation of Crystal Form-Controlled and Highly Crystalline BiVO4 Powder from Layered Vanadates at Room Temperature and Its Photocatalytic and Photophysical Properties. Am. Chem. Soc. 1999, 121, 11459–11467. [Google Scholar] [CrossRef]
  66. Liu, X.; Wang, F.; Wang, Q. Nanostructure-based WO3 photoanodes for photoelectrochemical water splitting. Phys. Chem. Chem. Phys. 2012, 14, 7894–7911. [Google Scholar] [CrossRef] [PubMed]
  67. Baniasadi, E.; Diner, I.; Naterer, G.F. Radiative heat transfer and catalyst performance in a large-scale continuous flow photoreactor for hydrogen production. Chem. Eng. Sci. 2012, 84, 638–645. [Google Scholar] [CrossRef]
  68. Wu, N.L.; Lee, M.S. Enhanced TiO2 photocatalysis by Cu in hydrogen production from aqueous methanol solution. Int. J. Hydrogen Energy 2004, 29, 1601. [Google Scholar] [CrossRef]
  69. Sakthivel, S.; Shankar, M.; Palanichamy, M.; Arabindoo, B.; Bahnemann, D.; Murugesan, V. Enhancement of photocatalytic activity by metal deposition: Characterisation and photonic efficiency of Pt, Au and Pd deposited on TiO2 catalyst. Water Res. 2004, 38, 3001–3008. [Google Scholar] [CrossRef] [PubMed]
  70. Kim, S.; Choi, W. Dual Photocatalytic Pathways of Trichloro acetate Degradation on TiO2: Effects of Nanosized Platinum Deposits on Kinetics and Mechanism. J. Phys. Chem. B 2002, 106, 13311–13317. [Google Scholar] [CrossRef]
  71. Jin, S.; Shiraishi, F. Photocatalytic activities enhanced for decompositions of organic compounds over metal-photo depositing titanium dioxide. Chem. Eng. J. 2004, 97, 203–211. [Google Scholar] [CrossRef]
  72. Subramanian, V.; Wolf, E.E.; Kamat, P.V. Catalysis with TiO2/Gold Nanocomposites. Effect of Metal Particle Size on the Fermi Level Equilibration. J. Am. Chem. Soc. 2004, 126, 4943–4950. [Google Scholar] [CrossRef]
  73. Tseng, I.-H.; Wu, J.C.S.; Chou, H.-Y. Effects of sol–gel procedures on the photocatalysis of Cu/TiO2 in CO2 photoreduction. J. Catal. 2004, 221, 432–440. [Google Scholar] [CrossRef]
  74. Liu, S.; Qu, Z.; Han, X.; Sun, C.L. A mechanism for enhanced photocatalytic activity of silver-loaded titanium dioxide. Catal. Today 2004, 93–95, 877–884. [Google Scholar] [CrossRef]
  75. Kamat, P.V.; Flumiani, M.; Dawson, A. Metal–metal and metal–semiconductor composite nanoclusters. Colloids Surf. A 2002, 202, 269–279. [Google Scholar] [CrossRef]
  76. Bardos, E.S.; Czili, H.; Horvath, A. Photocatalytic Degradation of Anionic Surfactant in Titanium Dioxide Suspension. J. Photochem. Photobiol. A 2003, 154, 195. [Google Scholar]
  77. Shen, S.; Guo, L.; Chen, X.; Ren, F.; Mao, S.S. Effect of Ag2S onsolar-driven photocatalytic hydrogen evolution of nanostructured CDs. Int. J. Hydrogen Energy 2010, 35, 7110–7115. [Google Scholar] [CrossRef]
  78. Shen, S.; Chen, X.; Ren, F.; Kronawitter, C.X.; Mao, S.S.; Guo, L. Solar light-driven photocatalytic hydrogen evolution overZnIn2S4 loaded with transition-metal sulfides. Nanoscale Res. Lett. 2011, 6, 290. [Google Scholar] [CrossRef]
  79. Mao, S.S.; Shen, S.; Guo, L. Liejin Guob Nanomaterials for renewable hydrogen production, storage and utilization. Prog. Nat. Sci. Mater. Int. 2012, 22, 522–534. [Google Scholar] [CrossRef] [Green Version]
  80. Singh, R.; Altaee, A.; Gautam, S. Nanomaterials in the advancement of hydrogen energy storage. Heliyon 2020, 6, e04487. [Google Scholar] [CrossRef]
  81. Wong-Foy, A.G.; Matzger, A.J.; Yaghi, O.M. ExceptionalH2 saturation uptake in microporous metal-organic frameworks. J. Am. Chem. Soc. 2006, 128, 3494–3495. [Google Scholar] [CrossRef]
  82. Report of the Basic Energy Science Workshop on Hydrogen Production, Storage and Use; Argonne National Laboratory: Lemont, IL, USA, 2003.
  83. Grochala, W.; Edwards, P.P. Thermal decomposition of the non-interstitial hydrides for the storage and production of hydrogen. Chem. Rev. 2004, 104, 1283–1316. [Google Scholar] [CrossRef]
  84. Sakintuna, B.; Lamari-Darkrim, F.; Hirscher, M. Metal hydride materials for solid hydrogen storage: A review. Int. J. Hydrog. Energy 2007, 32, 1121–1140. [Google Scholar] [CrossRef]
  85. Sherif, S.A.; Barbir, F.; Vieziroglu, T.N.; Mahishi, M.; Srinivasan, S.S. Hydrogen Energy Technologies. In Handbook of Energy Efficiency and Renewable Energy; Kreith, F., Goswami, D.Y., Eds.; Chapter 27; CRC Press: Boca Raton, FL, USA, 2007. [Google Scholar]
  86. Bogdanovic, B.; Schwickardi, M. Ti-doped alkali metal aluminium hydrides as potential novel reversible hydrogen storage materials. J. Alloys Compd. 1997, 253–254, 1–9. [Google Scholar] [CrossRef]
  87. Jensen, C.M.; Zidan, R.A. Hydrogen Storage Materials and Method of Making by Dry Homogenation. US Patent 6471935, 2002. [Google Scholar]
  88. Chen, P.; Xiong, Z.; Luo, J.; Lin, J.; Tan, K.L. Interaction of hydrogen with metal nitrides and imides. Nature 2002, 420, 302–304. [Google Scholar] [CrossRef] [PubMed]
  89. Hu, Y.H.; Ruckenstein, E. H2 Storage in Li3N. Temperature-Programmed Hydrogenation and Dehydrogenation. Ind. Eng. Chem. Res. 2003, 42, 5135–5139. [Google Scholar] [CrossRef]
  90. Vajo, J.J.; Skeith, S.L.; Mertens, F. Reversible storage of hydrogen in destabilized LiBH4. J. Phys. Chem. B 2005, 109, 3719–3722. [Google Scholar] [CrossRef] [PubMed]
  91. Au, M. Destabilized and Catalyzed Alkali Metal Borohydrides for Hydrogen Storage with Good Reversibility. US Patent Appl. Publ. 0194695, 2006. [Google Scholar]
  92. Srinivasan, S.S.; Escobar, D.; Jurczyk, M.; Goswami, Y.; Stefanakos, E.K. Nanocatalyst doping of Zn(BH4)2 for on-boardhydrogen storage. J. Alloys Compd. 2008, 462, 294–302. [Google Scholar] [CrossRef]
  93. Yang, J.; Sudik, A.; Siegel, D.J.; Halliday, D.; Drews, A.; Carter, R.O., III; Wolverton, C.; Lewis, G.J.; Sachtler, J.W.A.; Low, J.J.; et al. Hydrogen storage properties of 2LiNH2 + LiBH4 + MgH2. J. Alloys Compd. 2007, 446–447, 345–349. [Google Scholar] [CrossRef]
  94. Lewis, G.J.; Sachtler, J.W.A.; Low, J.J.; Lesch, D.A.; Faheem, S.A.; Dosek, P.M.; Knight, L.M.; Halloran, L.; Jensen, C.M.; Yang, J.; et al. High throughput screening of the ternary LiNH2-MgH2-LiBH4 phase diagram. J. Alloys Compd. 2007, 446–447, 355–359. [Google Scholar] [CrossRef]
  95. Lu, J.; Choi, Y.J.; Fang, Z.Z.; Sohn, H.Y.; Rçnnebro, E.J. Hydrogen Storage Properties of Nanosized MgH2−0.1TiH2 Prepared by Ultrahigh-Energy−High-Pressure Milling. Am. Chem. Soc. 2009, 131, 15843–15852. [Google Scholar] [CrossRef]
  96. Gutowska, A.; Li, L.Y.; Shin, Y.S.; Wang, C.M.M.; Li, X.H.S.; Linehan, J.C.; Smith, R.S.; Kay, B.D.; Schmid, B.; Shaw, W.; et al. Nanoscaffold mediates hydrogen release and the reactivity of ammonia borane. Angew. Chem. 2005, 117, 3644–3648. [Google Scholar] [CrossRef]
  97. Chaise, A.; de Rango, P.; Marty, P.; Fruchart, D. Experimental and numerical study of a magnesium hydride tank. Int. J. Hydrogen Energy 2010, 35, 6311–6322. [Google Scholar] [CrossRef]
  98. Chaise, A.; de Rango, P.; Marty, P.; Fruchart, D.; Miraglia, S.; Olives, R.; Garrier, S. Enhancement of hydrogen sorption in magnesium hydride using expanded natural graphite. Int. J. Hydrogen Energy 2009, 34, 8589–8596. [Google Scholar] [CrossRef]
  99. Pourpoint, T.L.; Sisto, A.; Smith, K.C.; Voskuilen, T.G.; Visaria, M.K.; Zheng, Y.; Fisher, T.S. Fisher, HT2008. In Proceedings of the ASME Summer Heat Transfer Conference, Jacksonville, FL, USA, 10–14 August 2008; Volume 1, pp. 37–46. [Google Scholar]
  100. Sudan, P.; Züttel, A.; Mauron, P.; Emmenegger, C.; Wenger, P.; Schlapbach, L. Physisorption of hydrogen in single walled carbon nanotubes. Carbon 2003, 41, 2377–2383. [Google Scholar] [CrossRef]
  101. Viswanathan, B.; Sankaran, M.; Schibioh, M.A. Carbonnanomaterials: Are they appropriate candidates for hydrogenstorage? Bull. Catal. Soc. India 2003, 2, 12–32. [Google Scholar]
  102. Nijkamp, M.G.; Raaymakers, J.E.M.J.; van Dillen, A.J.; de Jong, K.P. Hydrogen storage using physisorption—Materials demands. Appl. Phys. A 2001, 72, 619–623. [Google Scholar] [CrossRef] [Green Version]
  103. Dillon, A.C.; Jones, K.M.; Bekkedahl, T.A.; Kiang, C.H.; Bethune, D.S.; Heben, M.J. Storage of hydrogen in single-walled carbon nanotubes. Nature 1997, 386, 377–379. [Google Scholar] [CrossRef]
  104. Costa, P.M.F.J.; Coleman, K.S.; Green, M.L.H. Influence of catalyst metal particles on the hydrogen sorption of single walled carbon nanotube materials. Nanotechnology 2005, 16, 512–517. [Google Scholar] [CrossRef]
  105. Kroto, H.W.; Heath, J.R.; Brien, S.C.O.; Curl, R.F.; Smalley, R.E. C60: Buckminsterfullerene. Nature 1985, 318, 162–163. [Google Scholar] [CrossRef]
  106. Kojima, Y.; Kawai, Y. IR characterizations of lithium imideand amide. J. Alloys Compd. 2005, 395, 236–239. [Google Scholar] [CrossRef]
  107. Salehabadi, A.; Umar, M.F.; Ahmad, A.; Ahmad, M.I.; Ismail, N.; Rafatullah, M. Carbon-based nanocomposites in solid-state hydrogen storage technology: An overview. Int. J. Energy Res. 2020, 44, 11044–11058. [Google Scholar] [CrossRef]
  108. Poirier, E.; Chahine, R.; Be´nard, P.; Dorval-Douville, G.; Lafi, L.; Chandonia, P.A. Hydrogen Adsorption Measurements and Modeling on Metal-Organic Frameworks and Single-Walled Carbon Nanotubes. Langmuir 2006, 22, 8784. [Google Scholar] [CrossRef]
  109. Ding, R.G.; Finnerty, J.J.; Zhu, Z.H.; Yan, Z.F.; Lu, G.Q. Encyclopedia of Nanoscience and Nanotechnology; American Scientific Publishers: Valencia, CA, USA, 2004; Volume X, pp. 1–21. [Google Scholar]
  110. Ströbel, R.; Garche, J.; Moseley, P.T.; Jörissen, L.; Wolf, G. Hydrogen storage by carbon materials. J. Power Sources 2006, 159, 781. [Google Scholar] [CrossRef]
  111. Zhao, Y.; Kim, Y.-H.; Dillon, A.C.; Heben, M.J.; Zhang, S.B. Hydrogen Storage in Novel Organometallic Buckyballs. Phys. Rev. Lett. 2005, 94, 155504. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  112. Dillon, A.; Heben, M. Hydrogen storage using carbon adsorbents: Past, present and future. Appl. Phys. A 2001, 72, 133–142. [Google Scholar] [CrossRef]
  113. Chahine, R.; Bose, T.K. Low-pressure adsorption storage of hydrogen. Int. J. Hydrogen Energy 1994, 19, 161–164. [Google Scholar] [CrossRef]
  114. Li, H.; Eddaoudi, M.; O’Keeffe, M.; Yaghi, O.M. Design and synthesis of an exceptionally stable and highly porous metal-organic framework. Nature 1999, 402, 276–279. [Google Scholar] [CrossRef] [Green Version]
  115. Eddaoudi, M.; Moler, D.B.; Li, H.; Chen, B.; Reineke, T.M.; O’Keeffe, M.; Yaghi, O.M. Modular chemistry: Secondary building units as a basis for the design of highly porous and robust metal-organic carboxylate frameworks. Acc. Chem. Res. 2001, 34, 319–330. [Google Scholar] [CrossRef]
  116. Park, K.S.; Ni, Z.; Côté, A.P.; Choi, J.Y.; Huang, R.; Romo, F.J.U.; Chae, H.K.; O’Keeffe, M.; Yaghi, O.M. Exceptional chemical and thermal stability of zeolitic imidazolate frameworks. Proc. Natl. Acad. Sci. USA 2006, 103, 10186–10191. [Google Scholar] [CrossRef] [Green Version]
  117. Côté, A.P.; Bennin, A.I.; Ockwig, N.W.; O’Keeffe, M.; Matzger, A.; Yaghi, O.M. Porous, Crystalline, Covalent Organic Frameworks. Science 2005, 310, 1166–1170. [Google Scholar] [CrossRef] [Green Version]
  118. Fan, Y.-Y.; Kaufmann, A.; Mukasyan, A.; Varma, A. Single and multi-wall carbon nanotubes produced using the floating catalyst method: Synthesis, purification and hydrogen up take. Carbon 2006, 44, 2160–2170. [Google Scholar] [CrossRef]
  119. Panella, B.; Kossykh, L.; Dettlaff-Weglikowska, U.; Hirscher, M.; Zerbi, G.; Roth, S. Volumetric measurement of hydrogen storage in HCl-treated polyaniline and polypyrrole. Synth. Met. 2005, 151, 208–210. [Google Scholar] [CrossRef]
  120. Deng, F.; Zou, J.; Zhao, L.; Zhou, G.; Luo, X.; Luo, S. Chapter 3 Nanomaterial-Based Photocatalytic Hydrogen Production. In Nanomaterials for the Removal of Pollutants and Resource Reutilization; Elsevier: Amsterdam, The Netherlands, 2019; pp. 59–82. [Google Scholar]
  121. Balandin, A.A.; Ghosh, S.; Bao, W.; Calizo, I.; Teweldebrhan, D.; Miao, F.; Lau, C.N. Superior Thermal Conductivity of Single-Layer Graphene. Nano Lett. 2008, 8, 902–907. [Google Scholar] [CrossRef]
  122. Bolotin, K.; Sikes, K.; Jiang, Z.; Klima, M.; Fudenberg, G.; Hone, J.; Kim, P.; Stormer, H. Ultrahigh electron mobility in suspended graphene. Solid State Commun. 2008, 146, 351–355. [Google Scholar] [CrossRef] [Green Version]
  123. Stoller, M.D.; Park, S.; Zhu, Y.; An, J.; Ruoff, R.S. Graphene-Based Ultracapacitors. Nano Lett. 2008, 8, 3498–3502. [Google Scholar] [CrossRef]
  124. Lee, C.; Wei, X.; Kysar, J.W.; Hone, J. Measurement of the elastic properties and intrinsic strength of monolayer graphene. Science 2008, 321, 385–388. [Google Scholar] [CrossRef]
  125. Novoselov, K.S.; Jiang, D.; Schedin, F.; Booth, T.J.; Khotkevich, V.V.; Morozov, S.V.; Geim, A.K. Observation of electron-hole puddles in graphene using a scan ning single electron transistor. Proc. Natl. Acad. Sci. USA 2005, 102, 10451–10453. [Google Scholar] [CrossRef] [Green Version]
  126. Zhang, X.Y.; Li, H.P.; Cui, X.L.; He, Y. Graphene/TiO2 nanocomposites: Synthesis, characterization and application in hydrogen evolution from water photo cacatalyticc splitting. J. Mater. Chem. 2010, 20, 2801–2806. [Google Scholar] [CrossRef]
  127. Xie, H.; Hou, C.; Wang, H.; Zhang, Q.; Li, Y. S, N co-doped graphene quantumdot/TiO2 composites for efficient photocatalytic hydrogen generation. Nano. Res. Let. 2017, 12, 400–408. [Google Scholar] [CrossRef] [Green Version]
  128. Fan, W.; Lai, Q.; Zhang, Q.; Wang, Y. Nanocomposites of TiO2 and Reduced Graphene Oxide as Efficient Photocatalysts for Hydrogen Evolution. J. Phys. Chem. C 2011, 115, 10694–10701. [Google Scholar] [CrossRef]
  129. Hao, X.; Jin, Z.; Xu, J.; Min, S.; Lu, G. Functionalization of TiO2 with graphene quantum dots for efficient photocatalytic hydrogen evolution. Superlattices Microstruct. 2016, 94, 237–244. [Google Scholar] [CrossRef]
  130. Fan, X.; Chen, X.; Dai, L. 3D graphene based materials for energy storage. Curr. Opin. Colloid Interface Sci. 2015, 20, 429–438. [Google Scholar] [CrossRef]
  131. Ohashi, T. Carbon nanotubes in carbon nanomaterials foradvanced energy systems. In Advances in Materials Synthesis and Device Applications; Lu, W., Baek, J.-B., Dai, L., Eds.; John Wiley & Sons Inc.: Hoboken, NJ, USA, 2015. [Google Scholar] [CrossRef]
  132. Masjedi-Arani, M.; Salavati-Niasari, M. Cd2SiO4/Graphene nanocomposite: Ultrasonic assisted synthesis, characterization and electrochemical hydrogen storage application. Ultrason. Sonochemistry 2018, 43, 136–145. [Google Scholar] [CrossRef] [PubMed]
  133. Ngqalakwezi, A.; Nkazi, D.; Seifert, G.; Ntho, T. Effects of reduction of graphene oxide on the hydrogen storage capacities of metal graphene nanocomposite. Catal. Today 2019, 358, 338–344. [Google Scholar] [CrossRef]
  134. Cho, E.S.; Ruminski, A.M.; Aloni, S.; Liu, Y.-S.; Guo, Y.-S.L.J.; Urban, J.J. Graphene oxide/metal nanocrystal multilaminates as the atomic limit for safe and selective hydrogen storage. Nat. Commun. 2016, 7, 10804. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  135. Nivetha, R.; Grace, A.N. Manganese and zinc ferrite-based graphene nanocomposites for electrochemical hydrogen evolution reaction. J. Alloys Compd. 2019, 796, 185–195. [Google Scholar] [CrossRef]
  136. Tarasov, B.P.; Arbuzov, A.A.; Mozhzhuhin, S.A.; Volodin, A.; Fursikov, P.V.; Lototskyy, M.; Yartys, V.A. Hydrogen storage behavior of magnesium catalyzed by nickel-graphene nanocomposites. Int. J. Hydrogen Energy 2019, 44, 29212–29223. [Google Scholar] [CrossRef]
  137. Gholami, T.; Salavati-Niasari, M.; Sabet, M. Novel green synthesis of ZnAl2O4 and ZnAl2O4/graphene nanocomposite and comparison of electrochemical hydrogen storage and Coulombic efficiency. J. Clean. Prod. 2018, 178, 14–21. [Google Scholar] [CrossRef]
  138. Liu, Y.; Zhang, Z.; Hu, R. Synthesis of three-dimensional hierarchically porous reduced graphene oxide–TiO2 nanocomposite for enhanced hydrogen storage. Ceram. Int. 2018, 44, 12458–12465. [Google Scholar] [CrossRef]
  139. Du, J.; Lan, Z.; Zhang, H.; Lü, S.; Liu, H.; Guo, J. Catalytic enhanced hydrogen storage properties of Mg-based alloy by the addition of reduced graphene oxide supported V2O3 nanocomposite. J. Alloys Compd. 2019, 802, 660–667. [Google Scholar] [CrossRef]
  140. Jain, V.; Kandasubramanian, B. Functionalized graphene materials for hydrogen storage. J. Mater. Sci. 2019, 55, 1865–1903. [Google Scholar] [CrossRef]
  141. Ataca, C.; Akturk, E.; Ciraci, S.; Ustunel, H. High-capacity hydrogen storage by metallized graphene. Appl. Phys. Lett. 2008, 93, 043123. [Google Scholar] [CrossRef]
  142. Ataca, C.; Akturk, E.; Ciraci, S. Hydrogen storage of calcium atoms adsorbed on graphene: First-principles plane wave calculations. Phys. Rev. B Condens. Matter Mater. Phys. 2009, 79, 041406. [Google Scholar] [CrossRef]
  143. Wang, L.; Lee, K.; Sun, Y.-Y.; Lucking, M.; Chen, Z.; Zhao, J.J.; Zhang, S.B. Graphene Oxide as an Ideal Substrate for Hydrogen Storage. ACS Nano 2009, 3, 2995–3000. [Google Scholar] [CrossRef]
  144. Ao, Z.; Jiang, Q.; Zhang, R.; Tan, T.; Li, S. Al doped graphene: A promising material for hydrogen storage at room temperature. J. Appl. Phys. 2009, 105, 074307. [Google Scholar] [CrossRef] [Green Version]
  145. Er, S.; de Wijs, G.A.; Brocks, G. DFT Study of Planar Boron Sheets: A New Template for Hydrogen Storage. J. Phys. Chem. C 2009, 113, 18962–18967. [Google Scholar] [CrossRef] [Green Version]
  146. Li, D.; Ouyang, Y.; Li, J.; Sun, Y.; Chen, L. Hydrogen storage of beryllium adsorbed on graphene doping with boron: First-principles calculations. Solid State Commun. 2011, 152, 422–425. [Google Scholar] [CrossRef]
  147. Ao, Z.; Hernandez-Nieves, A.; Peeters, F.; Li, S. Electric Field Activated Hydrogen Dissociative Adsorption to Nitrogen-Doped Graphene. Phys. Chem. Chem. Phys. 2012, 14, 1463–1467. [Google Scholar] [CrossRef] [Green Version]
  148. Ozturk, Z.; Baykasoglu, C.; Kirca, M. Sandwiched graphene-fullerene composite: A novel 3-D nanostructured material for hydrogen storage. Int. J. Hydrog. Energy 2016, 41, 6403–6411. [Google Scholar] [CrossRef]
  149. Srinivas, G.; Zhu, Y.; Piner, R.; Skipper, N.; Ellerby, M.; Ruoff, R. Synthesis of graphene-like nanosheets and their hydrogen adsorption capacity. Carbon 2010, 48, 630–635. [Google Scholar] [CrossRef]
  150. Guo, C.X.; Wang, Y.; Li, C.M. Hierarchical Graphene-Based Material for Over 4.0 wt.% Physisorption Hydrogen Storage Capacity. ACS Sustain. Chem. Eng. 2012, 1, 14–18. [Google Scholar] [CrossRef]
  151. Aboutalebi, S.H.; Aminorroaya-Yamini, S.; Nevirkovets, I.; Konstantinov, K.; Liu, H.K. Enhanced Hydrogen Storage in Graphene Oxide-MWCNTs Composite at Room Temperature. Adv. Energy Mater. 2012, 2, 1439–1446. [Google Scholar] [CrossRef]
  152. Huang, C.-C.; Pu, N.-W.; Wang, C.-A.; Huang, J.-C.; Sung, Y.; Ger, M.-D. Hydrogen storage in graphene decorated with Pd and Pt nano-particles using an electroless deposition technique. Sep. Purif. Technol. 2011, 82, 210–215. [Google Scholar] [CrossRef]
  153. Parambhath, V.B.; Nagar, R.; Ramaprabhu, S. Effect of Nitrogen Doping on Hydrogen Storage Capacity of Palladium Decorated Graphene. Langmuir 2012, 28, 7826–7833. [Google Scholar] [CrossRef] [PubMed]
  154. Wang, Y.; Guo, C.X.; Wang, X.; Guan, C.; Yang, H.; Wang, K.; Li, C.M. Hydrogen storage in a Ni–B nanoalloy-doped three-dimensional graphene material. Energy Environ. Sci. 2010, 4, 195–200. [Google Scholar] [CrossRef]
  155. Liu, S.; Sun, L.; Xu, F.; Zhang, J.; Jiao, C.; Li, F.; Li, Z.; Wang, S.; Wang, Z.; Jiang, X.; et al. Nanosized Cu-MOFs induced by graphene oxide and enhanced gas storage capacity. Energy Environ. Sci. 2013, 6, 818. [Google Scholar] [CrossRef]
  156. Reguera, E. Materials for Hydrogen Storage in Nanocavities: Design criteria. Int. J. Hydrogen Energy 2009, 34, 9163–9167. [Google Scholar] [CrossRef]
  157. Reguera, L.; Balmaseda, J.; del Castillo, L.F. Hydrogen Storage in Porous Cyanometalates: Role of the Exchangeable Alkali Metal. J. Phys. Chem. C 2008, 112, 5589–5597. [Google Scholar] [CrossRef]
  158. Reguera, L.; Krap, C.P.; Balmaseda, J. Hydrogen Storage in Copper Prussian Blue Analogues: Evidence of H2 Coordination to the Copper Atom. J. Phys. Chem. C 2008, 112, 15893–15899. [Google Scholar] [CrossRef]
  159. Reguera, E. Hydrogen storage in nanocavities. Rev. Cuba. Física 2009, 26, 3–14. [Google Scholar]
  160. Niemann, M.U.; Srinivasan, S.S.; Phani, A.R.; Kumar, A.; Goswami, D.Y.; Stefanakos, E.K. Nanomaterials for Hydrogen Storage Applications: A Review. J. Nanomater. 2008, 2008, 950967. [Google Scholar] [CrossRef] [Green Version]
  161. Germain, J.; Fréchet, J.M.; Svec, F. Nanoporous polymers for hydrogen storage. Small 2009, 5, 1098–1111. [Google Scholar] [CrossRef]
Energies 15 09085 g001 550
Figure 1. An illustration of the process of photocatalytic water splitting for hydrogen production.
Figure 1. An illustration of the process of photocatalytic water splitting for hydrogen production.
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Figure 2. Results of a PubMed search showing hits pertaining to the keyword search on (a) hydrogen storage and nanomaterials, (b) hydrogen storage and carbon nanomaterials, and (c) hydrogen storage and graphene.
Figure 2. Results of a PubMed search showing hits pertaining to the keyword search on (a) hydrogen storage and nanomaterials, (b) hydrogen storage and carbon nanomaterials, and (c) hydrogen storage and graphene.
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Figure 3. Results of a PubMed search showing hits pertaining to the keyword search on (a) hydrogen production and nanomaterials, (b) hydrogen production and carbon nanomaterials, and (c) hydrogen production and graphene.
Figure 3. Results of a PubMed search showing hits pertaining to the keyword search on (a) hydrogen production and nanomaterials, (b) hydrogen production and carbon nanomaterials, and (c) hydrogen production and graphene.
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Table
Table 1. Graphene nanomaterial and its nanocomposites for hydrogen storage applications.
Table 1. Graphene nanomaterial and its nanocomposites for hydrogen storage applications.
Graphene TypeMaterial CompositionHydrogen StorageReference
Graphene nanocompositeGraphene/Li12.8 (maximum gravimetric density, wt.%)[141]
Graphene nanocompositeGraphene/Ca8.4 (maximum gravimetric density, wt.%)[142]
Graphene nanocompositeGraphene oxide/Ti4.9 (maximum gravimetric density, wt.%)[143]
Graphene nanocompositeGraphene/Al5.13 (maximum gravimetric density, wt.%)[144]
Graphene nanocompositeGraphene/Li/B10.7 (maximum gravimetric density, wt.%)[145]
Graphene nanocompositeBe adsorbed on B-doped graphene15.1 (maximum gravimetric density, wt.%)[146]
Graphene nanocompositeReduced graphene oxide/Mg6.5 (maximum gravimetric density, wt.%)[134]
Graphene nanocompositeN doped graphene7.23 (maximum gravimetric density, wt.%)[147]
Graphene nanocompositeLithium-doped fullerene/graphene5[148]
Graphene nanosheetsGraphene nanosheets1.2 wt.% 77 K[149]
GrapheneHierarchical graphene4.01 wt.% 77 K[150]
Graphene nanocompositeGraphene oxide MWCNT2.6 wt.% 298 K/50 bar[151]
Graphene nanocompositePt/Pd/Graphene0.156 303 K/57 bar[152]
Graphene nanocompositeN-doped palladium-decorated graphene2.10 wt.% 298 K/20 bar[153]
Graphene nanocompositeNi (0.83 wt.%) and B (1.09 wt.%) doped graphene4.4 wt.% 77 K/1.06 bar[154]
Graphene nanocompositeCu-BTC with 9 wt.% graphene3.58 wt.% 77 K/43 atm[155]
Graphene nanocompositeCd2SiO4/grapheneNot specified[132]
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Jawhari, A.H. Novel Nanomaterials for Hydrogen Production and Storage: Evaluating the Futurity of Graphene/Graphene Composites in Hydrogen Energy. Energies 2022, 15, 9085. https://doi.org/10.3390/en15239085

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Jawhari AH. Novel Nanomaterials for Hydrogen Production and Storage: Evaluating the Futurity of Graphene/Graphene Composites in Hydrogen Energy. Energies. 2022; 15(23):9085. https://doi.org/10.3390/en15239085

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Jawhari, Ahmed Hussain. 2022. "Novel Nanomaterials for Hydrogen Production and Storage: Evaluating the Futurity of Graphene/Graphene Composites in Hydrogen Energy" Energies 15, no. 23: 9085. https://doi.org/10.3390/en15239085

APA Style

Jawhari, A. H. (2022). Novel Nanomaterials for Hydrogen Production and Storage: Evaluating the Futurity of Graphene/Graphene Composites in Hydrogen Energy. Energies, 15(23), 9085. https://doi.org/10.3390/en15239085

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