Special Issue "10th Anniversary of Nanomaterials—Recent Advances in Nanomaterials for Energy and Catalysis"

A special issue of Nanomaterials (ISSN 2079-4991). This special issue belongs to the section "Energy and Catalysis".

Deadline for manuscript submissions: closed (31 December 2020).

Special Issue Editors

Prof. Dr. Nikolaos Dimitratos
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Guest Editor
Dipartimento di Chimica Industriale "Toso Montanari", Alma Mater Studiorum Università di Bologna, Viale Risorgimento 4, 40136 Bologna, Italy
Interests: heterogeneous catalysis; catalysis for energy; H2 production; CO2 transformation to methanol; biomass transformation; supported metal nanoparticles; heteropolyacids; biomass conversion; bifunctional catalysts; size and shape control of metal colloids; in situ and operando spectroscopy; advanced characterization using synchrotron and neutron techniques
Special Issues and Collections in MDPI journals
Dr. Alberto Villa
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Guest Editor
Dipartimento di Chimica, Università degli Studi di Milano, 20133 Milan, Italy
Interests: metal nanoparticles; heterogeneous catalysis; nanostructured metal oxides; functionalized carbons; metal carbides; biomass transformation
Special Issues and Collections in MDPI journals
Dr. Simon Freakley
E-Mail Website
Guest Editor
Department of Chemistry, University of Bath, 1 South, Claverton Down, Bath, BA2 7AY, UK
Interests: selective oxidation/reduction; catalyst preparation; supported nanoparticle catalysts, in situ spectroscopy
Special Issues and Collections in MDPI journals
Dr. Qian He
E-Mail Website
Guest Editor
Department of Materials Science and Engineering, National University of Singapore, Singapore, Singapore Country: Singapore
Interests: Advanced Electron Micrsocopy; heterogeneous catalysts; energy- and Environment-related nanomaterials; in situ electron microscopy; functional interfaces in materials

Special Issue Information

Dear Colleagues,

We are celebrating the 10th anniversary of Nanomaterials with a Special Issue in the Section “Energy and Catalysis” (ISSN 2079-4991; CODEN: NANOKO) in 2020.

On behalf of the Editors in Chief, Prof. Dr. Shirley Chiang, and members of the Editorial Office, and ourselves, we would like to take this opportunity to thank our authors and reviewers for their valuable contributions and for ensuring that Nanomaterials is a successful and respected journal in its field. To highlight this anniversary, we will be serving as Editors of a Special Issue that will cover various topics related to Energy and Catalysis.

We will seek papers on the understanding of the formation of metal nanoparticles with a specific focus on the morphology, including unsupported and supported colloidal nanoparticles with alloy and core–shell structures for (i) energy production including catalytic, photocatalytic, and electrochemical processes, (ii) biomass conversion, and (iii) sustainable chemical processes. Emphasis will be given to the (i) the rational design and synthesis of advanced nanomaterials, (ii) the basic and advanced characterization of understanding their structures and active sites, (iii) the understanding of the nanoparticle formation and reaction mechanisms, and (iv) computational methods for the design of nanomaterials and structure–activity correlations.

We intend to keep the scope of this Special Issue broad and adequately reflect the diversity and inclusiveness of the original research covered by Nanomaterials (https://www.mdpi.com/journal/nanomaterials).

On behalf of the Special Issue co-Editor and myself, we warmly invite the Nanomaterials community to submit their original work or an up-to-date review to this Special Issue, which will provide the readership with a comprehensive overview of many the topics covered by our discipline.

Prof. Dr. Nikolaos Dimitratos
Dr. Alberto Villa
Dr. Simon Freakley
Dr. Qian He
Guest Editors

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Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All papers will be peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Nanomaterials is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2200 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Published Papers (17 papers)

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Research

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Article
Effect of CO Molecule Orientation on the Reduction of Cu-Based Nanoparticles
Nanomaterials 2021, 11(2), 279; https://doi.org/10.3390/nano11020279 - 22 Jan 2021
Viewed by 408
Abstract
The adsorption of CO on the surface of Cu-based nanoparticles was studied in the presence of an external electric field by means of scanning tunneling microscopy (STM) and spectroscopy (STS). Nanoparticles were synthesized on the surface of a graphite support by the impregnation–precipitation [...] Read more.
The adsorption of CO on the surface of Cu-based nanoparticles was studied in the presence of an external electric field by means of scanning tunneling microscopy (STM) and spectroscopy (STS). Nanoparticles were synthesized on the surface of a graphite support by the impregnation–precipitation method. The chemical composition of the surface of the nanoparticles was determined as a mixture of Cu2O, Cu4O3 and CuO oxides. CO was adsorbed from the gas phase onto the surface of the nanoparticles. During the adsorption process, the potential differences ΔV = +1 or −1 V were applied to the vacuum gap between the sample and the grounded tip. Thus, the system of the STM tip and sample surface formed an asymmetric capacitor, inside which an inhomogeneous electric field existed. The CO adsorption process is accompanied by the partial reduction of nanoparticles. Due to the orientation of the CO molecule in the electric field, the reduction was weak in the case of a positive potential difference, while in the case of a negative potential difference, the reduction rate increased significantly. The ability to control the adsorption process of CO by means of an external electric field was demonstrated. The size of the nanoparticle was shown to be the key factor affecting the adsorption process, and particularly, the strength of the local electric field close to the nanoparticle surface. Full article
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Article
Synthesis of Two-Dimensional Sr-Doped LaNiO3 Nanosheets with Improved Electrochemical Performance for Energy Storage
Nanomaterials 2021, 11(1), 155; https://doi.org/10.3390/nano11010155 - 09 Jan 2021
Viewed by 553
Abstract
Designing a novel, efficient, and cost-effective nanostructure with the advantage of robust morphology and outstanding conductivity is highly promising for the electrode materials of high-performance electrochemical storage device. In this paper, a series of honeycombed perovskite-type Sr-doped LaNiO3 nanosheets with abundant porous [...] Read more.
Designing a novel, efficient, and cost-effective nanostructure with the advantage of robust morphology and outstanding conductivity is highly promising for the electrode materials of high-performance electrochemical storage device. In this paper, a series of honeycombed perovskite-type Sr-doped LaNiO3 nanosheets with abundant porous structure were successfully synthesized by accurately controlling the Sr-doped content. The study showed that the optimal LSNO-0.4 (La0.6Sr0.4NiO3-δ) electrode exhibited excellent electrochemical performance, which showed a high capacity of 115.88 mAh g−1 at 0.6 A g−1. Furthermore, a hybrid supercapacitor device (LSNO//AC) based on LSNO-0.4 composites and activated carbon (AC) showed a high energy density of 17.94 W h kg−1, a high power density of 1600 W kg−1, and an outstanding long-term stability with 104.4% capacity retention after 16,000 cycles, showing an excellent electrochemical performance and a promising application as an electrode for energy storage. Full article
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Article
Methylene Blue Dye Photocatalytic Degradation over Synthesised Fe3O4/AC/TiO2 Nano-Catalyst: Degradation and Reusability Studies
Nanomaterials 2020, 10(12), 2360; https://doi.org/10.3390/nano10122360 - 27 Nov 2020
Cited by 2 | Viewed by 673
Abstract
In this study, activated carbon (AC) from coconut shell, as a widely available agricultural waste, was synthesised in a simple one-step procedure and used to produce a magnetic Fe3O4/AC/TiO2 nano-catalyst for the degradation of methylene blue (MB) dye [...] Read more.
In this study, activated carbon (AC) from coconut shell, as a widely available agricultural waste, was synthesised in a simple one-step procedure and used to produce a magnetic Fe3O4/AC/TiO2 nano-catalyst for the degradation of methylene blue (MB) dye under UV light. Scanning electron microscopy revealed that TiO2 nanoparticles, with an average particle size of 45 to 62 nm, covered the surface of the AC porous structure without a reunion of its structure, which according to the TGA results enhanced the stability of the photocatalyst at high temperatures. The photocatalytic activities of synthesised AC, commercial TiO2, Fe3O4/AC, and Fe3O4/AC/TiO2 were compared, with Fe3O4/AC/TiO2 (1:2) exhibiting the highest catalytic activity (98%). Furthermore, evaluation of the recovery and reusability of the photocatalysts after treatment revealed that seven treatment cycles were possible without a significant reduction in the removal efficiency. Full article
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Article
ORR in Non-Aqueous Solvent for Li-Air Batteries: The Influence of Doped MnO2-Nanoelectrocatalyst
Nanomaterials 2020, 10(9), 1735; https://doi.org/10.3390/nano10091735 - 01 Sep 2020
Cited by 1 | Viewed by 722
Abstract
One of the major drawbacks in Lithium-air batteries is the sluggish kinetics of the oxygen reduction reaction (ORR). In this context, better performances can be achieved by adopting a suitable electrocatalyst, such as MnO2. Herein, we tried to design nano-MnO2 [...] Read more.
One of the major drawbacks in Lithium-air batteries is the sluggish kinetics of the oxygen reduction reaction (ORR). In this context, better performances can be achieved by adopting a suitable electrocatalyst, such as MnO2. Herein, we tried to design nano-MnO2 tuning the final ORR electroactivity by tailoring the doping agent (Co or Fe) and its content (2% or 5% molar ratios). Staircase-linear sweep voltammetries (S-LSV) were performed to investigate the nanopowders electrocatalytic behavior in organic solvent (propylene carbonate, PC and 0.15 M LiNO3 as electrolyte). Two percent Co-doped MnO2 revealed to be the best-performing sample in terms of ORR onset shift (of ~130 mV with respect to bare glassy carbon electrode), due to its great lattice defectivity and presence of the highly electroactive γ polymorph (by X-ray diffraction analyses, XRPD and infrared spectroscopy, FTIR). 5% Co together with 2% Fe could also be promising, since they exhibited fewer diffusive limitations, mainly due to their peculiar pore distribution (by Brunauer–Emmett-Teller, BET) that disfavored the cathode clogging. Particularly, a too-high Fe content led to iron segregation (by energy dispersive X-ray spectroscopy, EDX, X-ray photoelectron spectroscopy, XPS and FTIR) provoking a decrease of the electroactive sites, with negative consequences for the ORR. Full article
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Article
MOF-Derived Porous Fe2O3 Nanoparticles Coupled with CdS Quantum Dots for Degradation of Bisphenol A under Visible Light Irradiation
Nanomaterials 2020, 10(9), 1701; https://doi.org/10.3390/nano10091701 - 29 Aug 2020
Cited by 3 | Viewed by 835
Abstract
In this work, CdS quantum dots (QDs) were planted on magnetically recyclable porous Fe2O3 (denoted as F450) to obtain CdS QDs/porous Fe2O3 hybrids (denoted as X–CdS/F450, in which X is the immersion times of CdS QDs). Porous [...] Read more.
In this work, CdS quantum dots (QDs) were planted on magnetically recyclable porous Fe2O3 (denoted as F450) to obtain CdS QDs/porous Fe2O3 hybrids (denoted as X–CdS/F450, in which X is the immersion times of CdS QDs). Porous Fe2O3 was first obtained by pyrolysis from an iron-containing metal–organic framework by a two-step calcination method. Next, CdS QDs (of average size 3.0 nm) were uniformly and closely attached to the porous F450 via a sequential chemical-bath deposition strategy. As expected, the X–CdS/F450 hybrids serve as high-performance photocatalysts for the degradation of bisphenol A, a typical endocrine-disrupting chemical. Almost ∼100% of the bisphenol A was degraded over 5-CdS/F450 after visible light irradiation for 30 min (λ ≥ 420 nm). In comparison, the degradation efficiency of pure F450 powder is 59.2%. The high performance of 5-CdS/F450 may be ascribable to the fast electron transport of porous F450, the intense visible-light absorption of the CdS QDs and the matched energy levels between CdS and F450. More significantly, through the photocatalytic degradation reaction, the X–CdS/F450 hybrids can easily be recovered magnetically and reused in subsequent cycles, indicating their stability and recyclability. Full article
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Article
Dehydrogenation of Ethylene on Supported Palladium Nanoparticles: A Double View from Metal and Hydrocarbon Sides
Nanomaterials 2020, 10(9), 1643; https://doi.org/10.3390/nano10091643 - 21 Aug 2020
Cited by 4 | Viewed by 1142
Abstract
Adsorption of ethylene on palladium, a key step in various catalytic reactions, may result in a variety of surface-adsorbed species and formation of palladium carbides, especially under industrially relevant pressures and temperatures. Therefore, the application of both surface and bulk sensitive techniques under [...] Read more.
Adsorption of ethylene on palladium, a key step in various catalytic reactions, may result in a variety of surface-adsorbed species and formation of palladium carbides, especially under industrially relevant pressures and temperatures. Therefore, the application of both surface and bulk sensitive techniques under reaction conditions is important for a comprehensive understanding of ethylene interaction with Pd-catalyst. In this work, we apply in situ X-ray absorption spectroscopy, X-ray diffraction and infrared spectroscopy to follow the evolution of the bulk and surface structure of an industrial catalysts consisting of 2.6 nm supported palladium nanoparticles upon exposure to ethylene under atmospheric pressure at 50 °C. Experimental results were complemented by ab initio simulations of atomic structure, X-ray absorption spectra and vibrational spectra. The adsorbed ethylene was shown to dehydrogenate to C2H3, C2H2 and C2H species, and to finally decompose to palladium carbide. Thus, this study reveals the evolution pathway of ethylene on industrial Pd-catalyst under atmospheric pressure at moderate temperatures, and provides a conceptual framework for the experimental and theoretical investigation of palladium-based systems, in which both surface and bulk structures exhibit a dynamic nature under reaction conditions. Full article
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Article
Synthesis of a Rationally Designed Multi-Component Photocatalyst Pt:SiO2:TiO2(P25) with Improved Activity for Dye Degradation by Atomic Layer Deposition
Nanomaterials 2020, 10(8), 1496; https://doi.org/10.3390/nano10081496 - 30 Jul 2020
Cited by 1 | Viewed by 1077
Abstract
Photocatalysts for water purification typically lack efficiency for practical applications. Here we present a multi-component (Pt:SiO2:TiO2(P25)) material that was designed using knowledge of reaction mechanisms of mono-modified catalysts (SiO2:TiO2, and Pt:TiO2) combined with [...] Read more.
Photocatalysts for water purification typically lack efficiency for practical applications. Here we present a multi-component (Pt:SiO2:TiO2(P25)) material that was designed using knowledge of reaction mechanisms of mono-modified catalysts (SiO2:TiO2, and Pt:TiO2) combined with the potential of atomic layer deposition (ALD). The deposition of ultrathin SiO2 layers on TiO2 nanoparticles, applying ALD in a fluidized bed reactor, demonstrated in earlier studies their beneficial effects for the photocatalytic degradation of organic pollutants due to more acidic surface Si–OH groups which benefit the generation of hydroxyl radicals. Furthermore, our investigation on the role of Pt on TiO2(P25), as an improved photocatalyst, demonstrated that suppression of charge recombination by oxygen adsorbed on the Pt particles, reacting with the separated electrons to superoxide radicals, acts as an important factor for the catalytic improvement. Combining both materials into the resulting Pt:SiO2:TiO2(P25) nanopowder exceeded the dye degradation performance of both the individual SiO2:TiO2(P25) (1.5 fold) and Pt:TiO2(P25) (4-fold) catalysts by 6-fold as compared to TiO2(P25). This approach thus shows that by understanding the individual materials’ behavior and using ALD as an appropriate deposition technique enabling control on the nano-scale, new materials can be designed and developed, further improving the photocatalytic activity. Our research demonstrates that ALD is an attractive technology to synthesize multicomponent catalysts in a precise and scalable way. Full article
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Article
Nanoparticle Recognition on Scanning Probe Microscopy Images Using Computer Vision and Deep Learning
Nanomaterials 2020, 10(7), 1285; https://doi.org/10.3390/nano10071285 - 30 Jun 2020
Cited by 8 | Viewed by 1625
Abstract
Identifying, counting and measuring particles is an important component of many research studies. Images with particles are usually processed by hand using a software ruler. Automated processing, based on conventional image processing methods (edge detection, segmentation, etc.) are not universal, can only be [...] Read more.
Identifying, counting and measuring particles is an important component of many research studies. Images with particles are usually processed by hand using a software ruler. Automated processing, based on conventional image processing methods (edge detection, segmentation, etc.) are not universal, can only be used on good-quality images and need to set a number of parameters empirically. In this paper, we present results from the application of deep learning to automated recognition of metal nanoparticles deposited on highly oriented pyrolytic graphite on images obtained by scanning tunneling microscopy (STM). We used the Cascade Mask-RCNN neural network. Training was performed on a dataset containing 23 STM images with 5157 nanoparticles. Three images containing 695 nanoparticles were used for verification. As a result, the trained neural network recognized nanoparticles in the verification set with 0.93 precision and 0.78 recall. Predicted contour refining with 2D Gaussian function was a proposed option. The accuracies for mean particle size calculated from predicted contours compared with ground truth were in the range of 0.87–0.99. The results were compared with outcomes from other generally available software, based on conventional image processing methods. The advantages of deep learning methods for automatic particle recognition were clearly demonstrated. We developed a free open-access web service “ParticlesNN” based on the trained neural network, which can be used by any researcher in the world. Full article
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Article
Nanostructured BaCo0.4Fe0.4Zr0.1Y0.1O3-δ Cathodes with Different Microstructural Architectures
Nanomaterials 2020, 10(6), 1055; https://doi.org/10.3390/nano10061055 - 30 May 2020
Cited by 2 | Viewed by 817
Abstract
Lowering the operating temperature of solid oxide fuel cells (SOFCs) is crucial to make this technology commercially viable. In this context, the electrode efficiency at low temperatures could be greatly enhanced by microstructural design at the nanoscale. This work describes alternative microstructural approaches [...] Read more.
Lowering the operating temperature of solid oxide fuel cells (SOFCs) is crucial to make this technology commercially viable. In this context, the electrode efficiency at low temperatures could be greatly enhanced by microstructural design at the nanoscale. This work describes alternative microstructural approaches to improve the electrochemical efficiency of the BaCo0.4Fe0.4Zr0.1Y0.1O3-δ (BCFZY) cathode. Different electrodes architectures are prepared in a single step by a cost-effective and scalable spray-pyrolysis deposition method. The microstructure and electrochemical efficiency are compared with those fabricated from ceramic powders and screen-printing technique. A complete structural, morphological and electrochemical characterization of the electrodes is carried out. Reduced values of area specific resistance are achieved for the nanostructured cathodes, i.e., 0.067 Ω·cm2 at 600 °C, compared to 0.520 Ω·cm2 for the same cathode obtained by screen-printing. An anode supported cell with nanostructured BCFZY cathode generates a peak power density of 1 W·cm−2 at 600 °C. Full article
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Article
Development of Porous Titania Structure with Improved Photocatalytic Activity: Response Surface Modeling and Multi-Objective Optimization
Nanomaterials 2020, 10(5), 998; https://doi.org/10.3390/nano10050998 - 23 May 2020
Cited by 3 | Viewed by 834
Abstract
Porous titania was successfully synthesized by an ultrasound-assisted sol-gel route. The synthesis process was empirically modeled and optimized using the response surface methodology (RSM). Input variables adopted for optimization dealt with the weight ratio of precursors (r) and the sonication time [...] Read more.
Porous titania was successfully synthesized by an ultrasound-assisted sol-gel route. The synthesis process was empirically modeled and optimized using the response surface methodology (RSM). Input variables adopted for optimization dealt with the weight ratio of precursors (r) and the sonication time (t), representing the used factors in the synthesis procedure. With regard to application, the synthesized TiO2 samples were tested for the photodegradation of two water-soluble organic pollutants under UV–Vis irradiation. Optimal conditions for the efficient pollutants’ photodegradation were found to involve a precursors ratio of 3 and a sonication time of 60 min. Thus, the M5 sample prepared under the founded optimal conditions yielded the maximal removal efficiencies of 98.4% and 46.3% for the photodegradation of CR dye and 2,4-D herbicide, respectively. In addition, the photodegradation kinetics revealed the pseudo first-order rate constants, showing the photodegradation of CR (k1 = 8.86 × 10−2 min−1) by M5 sample is about 1.3-fold faster than the photodegradation of 2,4-D pesticide (k2 = 6.84 × 10−2 min−1). Full article
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Article
Photocatalytic Reduction of Cr(VI) in the Presence of Humic Acid Using Immobilized Ce–ZrO2 under Visible Light
Nanomaterials 2020, 10(4), 779; https://doi.org/10.3390/nano10040779 - 18 Apr 2020
Cited by 2 | Viewed by 1382
Abstract
Cr(VI) has several industrial applications but it is one of the most dangerous pollutants because of its carcinogenicity and high toxicity. Thus, the removal of Cr(VI) by photocatalytic reduction was investigated. The catalyst applied, Ce–ZrO2, was immobilized, through a sol–gel process [...] Read more.
Cr(VI) has several industrial applications but it is one of the most dangerous pollutants because of its carcinogenicity and high toxicity. Thus, the removal of Cr(VI) by photocatalytic reduction was investigated. The catalyst applied, Ce–ZrO2, was immobilized, through a sol–gel process on a silicon carbide (SiC) support, to increase the efficiency and avoid using suspended nanoparticles. The influence of initial pH, humic acid (HA), and catalyst dosage was investigated for Cr(VI) containing solutions. Then, a real galvanizing industry effluent (Cr(VI) = 77 mg L-1mg.L−1, Zn = 1789 mg L−1) was treated. It was observed that Cr(VI) adsorption and photoreduction are greatly favored at low pH values. HA can decrease Cr(VI) adsorption but also acts as holes scavenger, reducing the electron–hole recombination, favoring then the photoreduction. With the immobilized Ce–ZrO2, more than 97% of Cr(VI) was removed from the diluted effluent. These results indicate the feasibility to treat Cr(VI) effluents even in the presence of other metals and natural organic matter. The developed material has great chemical and mechanical resistances and avoids the use of nanoparticles, dangerous for the environment and hard to recover. Moreover, solar light can be used to drive the process, which contributes to the development of more sustainable, cleaner, and cost-effective wastewater treatments. Full article
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Article
Photoexcitation Processes in Oligomethine Cyanine Dyes for Dye-Sensitized Solar Cells—Synthesis and Computational Study
Nanomaterials 2020, 10(4), 662; https://doi.org/10.3390/nano10040662 - 02 Apr 2020
Cited by 3 | Viewed by 775
Abstract
We report density functional theory (DFT) calculations of three newly synthesized oligomethine cyanine-based dyes as potential TiO2-sensitizers in dye-sensitized solar cells. The three dyes have π-symmetry and the same acceptor side, terminating in the carboxylic anchor, but they differ through the [...] Read more.
We report density functional theory (DFT) calculations of three newly synthesized oligomethine cyanine-based dyes as potential TiO2-sensitizers in dye-sensitized solar cells. The three dyes have π-symmetry and the same acceptor side, terminating in the carboxylic anchor, but they differ through the π-bridge and the donor groups. We perform DFT and time-dependent DFT studies and present the electronic structure and optical properties of the dyes alone as well as adsorbed to the TiO2 nanocluster, to provide some predictions on the photovoltaic performance of the system. We analyze theoretically the factors that can influence the short circuit current and the open circuit voltage of the dye-sensitized solar cells. We examine the matching of the absorption spectra of the dye and dye-nanocluster system with the solar irradiation spectrum. We display the energy level diagrams and discuss the alignment between the excited state of the dyes and the conduction band edge of the oxide as well as between the redox level of the electrolyte and the ground state of the dyes. We determine the electron density of the key molecular orbitals and analyze comparatively the electron transfer from the dye to the semiconducting substrate. To put our findings in the right perspective we compare the results of our calculations with those obtained for a coumarin-based dye used in fabricating and testing actual devices, for which experimental data regarding the photovoltaic performance are available. Full article
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Review

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Review
A Review on New 3-D Printed Materials’ Geometries for Catalysis and Adsorption: Paradigms from Reforming Reactions and CO2 Capture
Nanomaterials 2020, 10(11), 2198; https://doi.org/10.3390/nano10112198 - 04 Nov 2020
Cited by 1 | Viewed by 844
Abstract
“Bottom-up” additive manufacturing (AM) is the technology whereby a digitally designed structure is built layer-by-layer, i.e., differently than by traditional manufacturing techniques based on subtractive manufacturing. AM, as exemplified by 3D printing, has gained significant importance for scientists, among others, in the fields [...] Read more.
“Bottom-up” additive manufacturing (AM) is the technology whereby a digitally designed structure is built layer-by-layer, i.e., differently than by traditional manufacturing techniques based on subtractive manufacturing. AM, as exemplified by 3D printing, has gained significant importance for scientists, among others, in the fields of catalysis and separation. Undoubtedly, it constitutes an enabling pathway by which new complex, promising and innovative structures can be built. According to recent studies, 3D printing technologies have been utilized in enhancing the heat, mass transfer, adsorption capacity and surface area in CO2 adsorption and separation applications and catalytic reactions. However, intense work is needed in the field to address further challenges in dealing with the materials and metrological features of the structures involved. Although few studies have been performed, the promise is there for future research to decrease carbon emissions and footprint. This review provides an overview on how AM is linked to the chemistry of catalysis and separation with particular emphasis on reforming reactions and carbon adsorption and how efficient it could be in enhancing their performance. Full article
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Review
Sulfide and Oxide Inorganic Solid Electrolytes for All-Solid-State Li Batteries: A Review
Nanomaterials 2020, 10(8), 1606; https://doi.org/10.3390/nano10081606 - 15 Aug 2020
Cited by 26 | Viewed by 4177
Abstract
Energy storage materials are finding increasing applications in our daily lives, for devices such as mobile phones and electric vehicles. Current commercial batteries use flammable liquid electrolytes, which are unsafe, toxic, and environmentally unfriendly with low chemical stability. Recently, solid electrolytes have been [...] Read more.
Energy storage materials are finding increasing applications in our daily lives, for devices such as mobile phones and electric vehicles. Current commercial batteries use flammable liquid electrolytes, which are unsafe, toxic, and environmentally unfriendly with low chemical stability. Recently, solid electrolytes have been extensively studied as alternative electrolytes to address these shortcomings. Herein, we report the early history, synthesis and characterization, mechanical properties, and Li+ ion transport mechanisms of inorganic sulfide and oxide electrolytes. Furthermore, we highlight the importance of the fabrication technology and experimental conditions, such as the effects of pressure and operating parameters, on the electrochemical performance of all-solid-state Li batteries. In particular, we emphasize promising electrolyte systems based on sulfides and argyrodites, such as LiPS5Cl and β-Li3PS4, oxide electrolytes, bare and doped Li7La3Zr2O12 garnet, NASICON-type structures, and perovskite electrolyte materials. Moreover, we discuss the present and future challenges that all-solid-state batteries face for large-scale industrial applications. Full article
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Review
A Review about the Recent Advances in Selected NonThermal Plasma Assisted Solid–Gas Phase Chemical Processes
Nanomaterials 2020, 10(8), 1596; https://doi.org/10.3390/nano10081596 - 14 Aug 2020
Cited by 4 | Viewed by 1041
Abstract
Plasma science has attracted the interest of researchers in various disciplines since the 1990s. This continuously evolving field has spawned investigations into several applications, including industrial sterilization, pollution control, polymer science, food safety and biomedicine. nonthermal plasma (NTP) can promote the occurrence of [...] Read more.
Plasma science has attracted the interest of researchers in various disciplines since the 1990s. This continuously evolving field has spawned investigations into several applications, including industrial sterilization, pollution control, polymer science, food safety and biomedicine. nonthermal plasma (NTP) can promote the occurrence of chemical reactions in a lower operating temperature range, condition in which, in a conventional process, a catalyst is generally not active. The aim, when using NTP, is to selectively transfer electrical energy to the electrons, generating free radicals through collisions and promoting the desired chemical changes without spending energy in heating the system. Therefore, NTP can be used in various fields, such as NOx removal from exhaust gases, soot removal from diesel engine exhaust, volatile organic compound (VOC) decomposition, industrial applications, such as ammonia production or methanation reaction (Sabatier reaction). The combination of NTP technology with catalysts is a promising option to improve selectivity and efficiency in some chemical processes. In this review, recent advances in selected nonthermal plasma assisted solid–gas processes are introduced, and the attention was mainly focused on the use of the dielectric barrier discharge (DBD) reactors. Full article
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Review
Breakthroughs in the Design of Novel Carbon-Based Metal Oxides Nanocomposites for VOCs Gas Sensing
Nanomaterials 2020, 10(8), 1485; https://doi.org/10.3390/nano10081485 - 29 Jul 2020
Cited by 10 | Viewed by 1022
Abstract
Nowadays, the detection of volatile organic compounds (VOCs) at trace levels (down to ppb) is feasible by exploiting ultra-sensitive and highly selective chemoresistors, especially in the field of medical diagnosis. By coupling metal oxide semiconductors (MOS e.g., SnO2, ZnO, WO3 [...] Read more.
Nowadays, the detection of volatile organic compounds (VOCs) at trace levels (down to ppb) is feasible by exploiting ultra-sensitive and highly selective chemoresistors, especially in the field of medical diagnosis. By coupling metal oxide semiconductors (MOS e.g., SnO2, ZnO, WO3, CuO, TiO2 and Fe2O3) with innovative carbon-based materials (graphene, graphene oxide, reduced graphene oxide, single-wall and multi-wall carbon nanotubes), outstanding performances in terms of sensitivity, selectivity, limits of detection, response and recovery times towards specific gaseous targets (such as ethanol, acetone, formaldehyde and aromatic compounds) can be easily achieved. Notably, carbonaceous species, highly interconnected to MOS nanoparticles, enhance the sensor responses by (i) increasing the surface area and the pore content, (ii) favoring the electron migration, the transfer efficiency (spillover effect) and gas diffusion rate, (iii) promoting the active sites concomitantly limiting the nanopowders agglomeration; and (iv) forming nano-heterojunctions. Herein, the aim of the present review is to highlight the above-mentioned hybrid features in order to engineer novel flexible, miniaturized and low working temperature sensors, able to detect specific VOC biomarkers of a human’s disease. Full article
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Review
Carbon Nanohorn-Based Electrocatalysts for Energy Conversion
Nanomaterials 2020, 10(7), 1407; https://doi.org/10.3390/nano10071407 - 19 Jul 2020
Cited by 5 | Viewed by 937
Abstract
In the context of even more growing energy demands, the investigation of alternative environmentally friendly solutions, like fuel cells, is essential. Given their outstanding properties, carbon nanohorns (CNHs) have come forth as promising electrocatalysts within the nanocarbon family. Carbon nanohorns are conical nanostructures [...] Read more.
In the context of even more growing energy demands, the investigation of alternative environmentally friendly solutions, like fuel cells, is essential. Given their outstanding properties, carbon nanohorns (CNHs) have come forth as promising electrocatalysts within the nanocarbon family. Carbon nanohorns are conical nanostructures made of sp2 carbon sheets that form aggregated superstructures during their synthesis. They require no metal catalyst during their preparation and they are inexpensively produced in industrial quantities, affording a favorable candidate for electrocatalytic reactions. The aim of this article is to provide a comprehensive overview regarding CNHs in the field of electrocatalysis and especially, in oxygen reduction, methanol oxidation, and hydrogen evolution, as well as oxygen evolution from water splitting, underlining the progress made so far, and pointing out the areas where significant improvement can be achieved. Full article
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