Next Article in Journal
Rhodium Oxide Surface-Loaded Gas Sensors
Previous Article in Journal
Poly(vinylidene fluoride) and Carbon Derivative Structures from Eco-Friendly MOF-5 for Supercapacitor Electrode Preparation with Improved Electrochemical Performance
Previous Article in Special Issue
Insights into Metal Oxide and Zero-Valent Metal Nanocrystal Formation on Multiwalled Carbon Nanotube Surfaces during Sol-Gel Process
Article Menu
Issue 11 (November) cover image

Export Article

Nanomaterials 2018, 8(11), 891; https://doi.org/10.3390/nano8110891

Editorial
Preparation and Application of Hybrid Nanomaterials
1
Dipartimento di Chimica, Università degli Studi di Milano, Via Golgi 19, 20133 Milano, Italy
2
Consorzio Interuniversitario Nazionale per la Scienza e la Tecnologia dei Materiali (INSTM), Via Giusti 9, 50121 Firenze, Italy
*
Authors to whom correspondence should be addressed.
Received: 23 October 2018 / Accepted: 30 October 2018 / Published: 1 November 2018
The growing demand of new materials with tailored physicochemical properties has propelled hybrid materials to a position of prominence in materials science by virtue of their remarkable new properties and multifunctional nature. Hybrid nanomaterials, formed by two or more components connected at the nanometer scale, combine the intrinsic characteristics of its individual constituents to additional properties due to synergistic effects between the components [1,2]. As a result, the properties of hybrid nanomaterials can be tuned by changing their composition and morphology, leading to materials with enhanced performance characteristics, such as high thermal stability, mechanical strength, light emission, gas permeability, electron conductivity, and controlled wetting features [3,4]. Owing to their wide spectrum of accessible properties, hybrid materials are emerging platforms for applications in extremely diverse fields such as optics, microelectronics, smart coatings, health and diagnostics, photovoltaics, fuel cells, pollutant remediation, catalysis, and sensing [5,6,7,8]. This Special Issue, with a collection of 13 original contributions and two literature overviews, showcases some of the latest advances in this burgeoning and highly interdisciplinary research field, with the aim of highlighting potential applications in diverse fields, present challenges, and research outlooks.
Several articles in this Special Issue focus on the synthesis of materials or devices designed for pollution remediation. In the feature article by Liao et al. [9], hybrid surface coatings were prepared by modifying TiO2 films with Au nanoclusters by gas-phase beam deposition. The gold distribution onto the semiconductor support was highly homogeneous and provided efficient plasmonic photocatalytic activity. Tests of stearic acid degradation performed both under UV and green LED light showed a promoting effect due to the metal nanoclusters, especially under green light irradiation. The feature paper by Panzarasa and coauthors [10] presents a different approach to pollutant remediation, making use of natural renewable sources. Sepia melanin was used as an active component in hybrid adsorbent materials, owing to its ability to efficiently bind several organic compounds. The resulting hybrid material proved efficient, stable, easily recoverable and showed good reusability. Also in the work by Ren and coauthors [11], agro-alimentary waste is valorized as a starting material for hybrid material preparation. Magnetite-carbon nanocomposites were prepared by a hydrothermal procedure adopting pomelo peels as carbon source. The resulting hybrids were used as adsorbents to extract fungicide residues from homogenized fruit samples. One of the main issues in the pollutant remediation of surface waters and wastewaters by adsorption and/or degradation processes is represented by the removal of finely dispersed adsorbents/photocatalysts upon treatment. In the work by Lu and coauthors [12], a magnetic separation procedure is proposed to solve this problem: Hybrid magnetic iron oxides were deposited onto MoS2 nanosheets in the presence of metallic iron. By combining direct redox and Fenton processes, the hybrid provided simultaneous degradation of both toxic inorganic (Cr(VI)) and organic compounds (4-chlorophenol). Moreover, the nanocomposites could be separated magnetically from the treated effluent, showing good reusability.
In the last decade, hybrids based on carbon nanomaterials, such as carbon nanotubes, have raised a great deal of interest in several fields [13,14]. In the work by Das and coauthors [15], the in situ formation of either crystalline metals or metal oxides onto multiwalled carbon nanotubes (MWNT) was achieved by modifying the sol-gel conditions of the precipitation reaction, in the absence of any oxidizing or reducing agent, using the electrochemical potential as a control parameter. The reaction occurrence was made possible just by the surface energy and composition of the MWNT activated surfaces, which act as nucleation sites for the growth of the crystals. By the same principles, in the feature paper by Sansotera et al. [16], the successful functionalization of MWNT by perfluoropolyether chains was controlled by the surface features of the carbon nanotubes. The resulting covalent bond produced relevant modifications of the MWNT surface energy imparting superhydrophobic behavior; branched chains, bearing CF3 groups, produced a higher functionalization degree with respect to linear ones. The functionalization appeared to affect the pore size distribution of MWNT, mainly in the case of branched chains, while the conduction properties were only weakly modified. The control of the porosity and surface features of carbon materials is also the focus of the work by Lu and coauthors [17]. They proposed a controlled modification of mesoporous carbon by Mg and N in the presence of a non-ionic surfactant, giving rise to a higher microporosity and to two types of basic sites. Thanks to the enhanced morphological and surface features, the resulting materials showed increased CO2 adsorption, more than twice with respect to the pristine material.
Another field of applied science currently benefitting from hybrid materials is health care. Potential biomedical applications are envisaged in the works by Truong et al. [18] and by Predoi et al. [19]. Truong and coauthors [18] reported the synthesis of vertically aligned Cu-doped Zn nanorods grown on a platform of Cu3Si nanoblocks. The prepared nanocomposites showed an extended absorption edge and bioluminescence in the visible region, which paves the way to their application as bio-probes and luminescent markers. The work of Predoi et al. [19] deals with the very important topic of alternative antimicrobial agents for disinfection. Antibiotic resistance is becoming an increasingly major concern worldwide and has prompted the research of alternative treatments or medications. Predoi and coauthors [19] described the antimicrobial activity of essential oils deposited onto hydroxyapatite: Hydroxyapatite coated by lavender essential oil showed higher antibacterial activity with respect to other essential oil and, thanks to its biocompatibility, could be proposed to combat infections following prosthetic implantation. Regenerative medicine is also the topic of the review article by Batool et al. [20], more specifically, the new bioengineering approaches in terms of periodontal tissues and bone regeneration. The review sheds light on the use of bioactive hybrid scaffolds, such as functionalized membranes, for the controlled local delivery of anti-inflammatory drugs and growth factors for the treatment of periodontal diseases.
The Special Issue showcases a broad range of application areas of hybrid devices, including self-cleaning coatings [21], sensors [22], catalysis [23], optoelectronics [24], and photovoltaics [25]. The feature article by Vázquez-Velázquez et al. [21] presented covalently functionalized TiO2–SiO2 binary systems dispersed in an acrylic matrix, giving rise to hybrid films with excellent transparency and superhydrophilic properties. The authors discussed the synergistic effects in the nanocomposite on the grounds of the chemical interactions among the constituents and their morphology.
Wang and coauthors [22] reported a carefully designed hydrothermal synthesis giving rise to beautiful flower-like nanocomposites based on SnO2 nanorods and nano-sheet graphitic carbon nitride. The hybrid materials showed promising results as gas sensors for ethanol detection: The improved sensor response of the hybrids with respect to literature data, is discussed on the grounds of the band structure, resulting from the heterojunction between the two semiconductors, and of the increased number of gas adsorption sites.
The synthetic approach plays a key role also in the work by Jodłowski and coauthors [23] where the preparation of nanocomposites between zirconia and non-noble metal oxides, to be used as catalysts for methane combustion, was promoted by sonochemistry. The ultrasound treatment produced an optimal dispersion of the oxides onto the support leading to enhanced catalytic activity.
The communication by Kim et al. [24] presents a transparent and conductive hybrid material for use as transparent electrode in flexible electronics. Bidimensional silver nanowires deposited onto PET layers and decorated with nanometric Ti layers were proposed as a flexible substitute to conventional transparent conductive oxides, such as indium tin oxide (ITO). The titanium layer, deposited by electron-beam evaporation, imparted improved ambient-stability under high-temperature and high-humidity conditions and promoted a net increase in the electrical conductivity with respect to the pristine materials, yielding an 88% transparency rate and an electrical performance that is better than commercial transparent conductive electrodes.
The Special Issue is completed by a review article by Wu and coauthors [25] dealing with a very high profile topic in the energy conversion community: Perovskite-based solar cells (PSCs). Organic-inorganic perovskites have raised world-wide attention in recent years due to their unique electronic, optical and transport properties. In the last few years the power conversion efficiency of PSCs has increased explosively from 3.8% (2009) to about 22% (2017) [26]. However, the stability of perovskite solar cell devices is still unsatisfactory, particularly in the presence of moisture and light illumination. The role played by composition, structure and hybrid architectures were examined in detail in the review and the material design was proposed as a tool to control the material stability and conversion efficiency.
In summary, this Special Issue of Nanomaterials titled “Preparation and Application of Hybrid Nanomaterials” compiles a series of original research articles and review papers providing new insight on the preparation and on the wealth of applications of hybrid nanomaterials. We are confident that this Special Issue will provide the reader with an overall view of the latest prospects in this fast evolving and cross-disciplinary field.

Funding

This research received no external funding.

Acknowledgments

The Editors would like to thank all authors of this Special Issue of Nanomaterials for their excellent contributions. We gratefully acknowledge all the colleagues who served as reviewers for this Special Issue, as their critical contribution was instrumental in raising the overall quality of the publications. We would like to express our deep appreciation to the publishing team for their constant support and assistance.

Conflicts of Interest

The authors declare no conflicts of interest.

References

  1. Loy, D.A.; Shea, K.J. Bridged Polysilsesquioxanes. Highly Porous Hybrid Organic-Inorganic Materials. Chem. Rev. 1995, 95, 1431–1442. [Google Scholar] [CrossRef]
  2. Díaz, U.; Brunel, D.; Corma, A. Catalysis using multifunctional organosiliceous hybrid materials. Chem. Soc. Rev. 2013, 42, 4083–4097. [Google Scholar] [CrossRef] [PubMed]
  3. Hayami, R.; Wada, K.; Nishikawa, I.; Sagawa, T.; Yamamoto, K.; Tsukada, S.; Gunji, T. Preparation and properties of organic–inorganic hybrid materials using titanium phosphonate cluster. Polym. J. 2017, 49, 665–669. [Google Scholar] [CrossRef]
  4. Soliveri, G.; Annunziata, R.; Ardizzone, S.; Cappelletti, G.; Meroni, D. Multiscale Rough Titania Films with Patterned Hydrophobic/Oleophobic Features. J. Phys. Chem. C 2012, 116, 26405–26413. [Google Scholar] [CrossRef]
  5. Diaz, U.; Corma, A. Organic-Inorganic Hybrid Materials: Multi-Functional Solids for Multi-Step Reaction Processes. Chem. Eur. J. 2018, 24, 3944–3958. [Google Scholar] [CrossRef] [PubMed]
  6. Meroni, D.; Ardizzone, S.; Schubert, U.S.; Höppener, S. Probe-Based Electro-Oxidative Lithography of OTS SAMs Deposited onto Transparent ITO Substrates. Adv. Funct. Mater. 2012, 22, 4376–4382. [Google Scholar] [CrossRef]
  7. Sanchez, C.; Belleville, P.; Popall, M.; Nicole, L. Applications of advanced hybrid organic-inorganic nanomaterials: From laboratory to market. Chem. Soc. Rev. 2011, 40, 696–753. [Google Scholar] [CrossRef] [PubMed]
  8. Colombo, A.; Dragonetti, C.; Magni, M.; Meroni, D.; Ugo, R.; Marotta, G.; Lobello, M.G.; Salvatori, P.; De Angelis, F. New thiocyanate-free ruthenium(II) sensitizers with different pyrid-2-yl tetrazolate ligands for dye-sensitized solar cells. Dalton Trans. 2015, 44, 11788–11796. [Google Scholar] [CrossRef] [PubMed]
  9. Liao, T.-W.; Verbruggen, S.W.; Claes, N.; Yadav, A.; Grandjean, D.; Bals, S.; Lievens, P. TiO2 Films Modified with Au Nanoclusters as Self-Cleaning Surfaces under Visible Light. Nanomaterials 2018, 8, 30. [Google Scholar] [CrossRef] [PubMed]
  10. Panzarasa, G.; Osypova, A.; Consolati, G.; Quasso, F.; Soliveri, G.; Ribera, J.; Schwarze, F.W.M.R. Preparation of a Sepia Melanin and Poly(ethylene-alt-maleic Anhydride) Hybrid Material as an Adsorbent for Water Purification. Nanomaterials 2018, 8, 54. [Google Scholar] [CrossRef] [PubMed]
  11. Ren, K.; Zhang, W.; Cao, S.; Wang, G.; Zhou, Z. Carbon-Based Fe3O4 Nanocomposites Derived from Waste Pomelo Peels for Magnetic Solid-Phase Extraction of 11 Triazole Fungicides in Fruit Samples. Nanomaterials 2018, 8, 302. [Google Scholar] [CrossRef] [PubMed]
  12. Lu, H.; Wang, J.; Hao, H.; Wang, T. Magnetically Separable MoS2/Fe3O4/nZVI Nanocomposites for the Treatment of Wastewater Containing Cr(VI) and 4-Chlorophenol. Nanomaterials 2017, 7, 303. [Google Scholar] [CrossRef] [PubMed]
  13. Desmecht, A.; Steenhaut, T.; Pennetreau, F.; Hermans, S.; Riant, O. Synthesis and Catalytic Applications of Multi-Walled Carbon Nanotube–Polyamidoamine Dendrimer Hybrids. Chem. Eur. J. 2018, 24, 12992–13001. [Google Scholar] [CrossRef] [PubMed]
  14. Yin, P.T.; Shah, S.; Chhowalla, M.; Lee, K.B. Design, synthesis, and characterization of graphene-nanoparticle hybrid materials for bioapplications. Chem. Rev. 2015, 115, 2483–2531. [Google Scholar] [CrossRef] [PubMed]
  15. Das, D.; Sabaraya, I.V.; Sabo-Attwood, T.; Saleh, N.B. Insights into Metal Oxide and Zero-Valent Metal Nanocrystal Formation on Multiwalled Carbon Nanotube Surfaces during Sol-Gel Process. Nanomaterials 2018, 8, 403. [Google Scholar] [CrossRef] [PubMed]
  16. Sansotera, M.; Talaeemashhadi, S.; Gambarotti, C.; Pirola, C.; Longhi, M.; Ortenzi, M.A.; Navarrini, W.; Bianchi, C.L. Comparison of Branched and Linear Perfluoropolyether Chains Functionalization on Hydrophobic, Morphological and Conductive Properties of Multi-Walled Carbon Nanotubes. Nanomaterials 2018, 8, 176. [Google Scholar] [CrossRef] [PubMed]
  17. Lu, J.; Jiao, C.; Majeed, Z.; Jiang, H. Magnesium and Nitrogen Co-Doped Mesoporous Carbon with Enhanced Microporosity for CO2 Adsorption. Nanomaterials 2018, 8, 275. [Google Scholar] [CrossRef] [PubMed]
  18. Truong, J.; Hansen, M.; Szychowski, B.; Xie, T.; Daniel, M.-C.; Hahm, J. Spatially Correlated, Single Nanomaterial-Level Structural and Optical Profiling of Cu-Doped ZnO Nanorods Synthesized via Multifunctional Silicides. Nanomaterials 2018, 8, 222. [Google Scholar] [CrossRef] [PubMed]
  19. Predoi, D.; Iconaru, S.L.; Buton, N.; Badea, M.L.; Marutescu, L. Antimicrobial Activity of New Materials Based on Lavender and Basil Essential Oils and Hydroxyapatite. Nanomaterials 2018, 8, 291. [Google Scholar] [CrossRef] [PubMed]
  20. Batool, F.; Strub, M.; Petit, C.; Bugueno, I.M.; Bornert, F.; Clauss, F.; Huck, O.; Kuchler-Bopp, S.; Benkirane-Jessel, N. Periodontal Tissues, Maxillary Jaw Bone, and Tooth Regeneration Approaches: From Animal Models Analyses to Clinical Applications. Nanomaterials 2018, 8, 337. [Google Scholar] [CrossRef] [PubMed]
  21. Vázquez-Velázquez, A.R.; Velasco-Soto, M.A.; Pérez-García, S.A.; Licea-Jiménez, L. Functionalization Effect on Polymer Nanocomposite Coatings Based on TiO2–SiO2 Nanoparticles with Superhydrophilic Properties. Nanomaterials 2018, 8, 369. [Google Scholar] [CrossRef] [PubMed]
  22. Wang, Y.; Cao, J.; Qin, C.; Zhang, B.; Sun, G.; Zhang, Z. Synthesis and Enhanced Ethanol Gas Sensing Properties of the g-C3N4 Nanosheets-Decorated Tin Oxide Flower-Like Nanorods Composite. Nanomaterials 2017, 7, 285. [Google Scholar] [CrossRef] [PubMed]
  23. Jodłowski, P.J.; Jedrzejczyk, R.J.; Chlebda, D.K.; Dziedzicka, A.; Kuterasinski, Ł.; Gancarczyk, A.; Sitarz, M. Non-Noble Metal Oxide Catalysts for Methane Catalytic Combustion: Sonochemical Synthesis and Characterisation. Nanomaterials 2017, 7, 174. [Google Scholar] [CrossRef] [PubMed]
  24. Kim, Y.-M.; Hwang, B.-Y.; Lee, K.-W.; Kim, J.-Y. Ambient-Stable and Durable Conductive Ag-Nanowire-Network 2-D Films Decorated with a Ti Layer. Nanomaterials 2018, 8, 321. [Google Scholar] [CrossRef] [PubMed]
  25. Wu, Y.; Chen, W.; Chen, G.; Liu, L.; He, Z.; Liu, R. The Impact of Hybrid Compositional Film/Structure on Organic–Inorganic Perovskite Solar Cells. Nanomaterials 2018, 8, 356. [Google Scholar] [CrossRef] [PubMed]
  26. National Renewable Energy Laboratory (NREL) Best Research-Cell Efficiencies. Available online: https://www.nrel.gov/pv/assets/pdfs/pv-efficiencies-07-17-2018.pdf (accessed on 23 October 2018).

© 2018 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
Nanomaterials EISSN 2079-4991 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top