Download or read book Formation Mechanisms and Photocatalytic Properties of ZnO based Nanomaterials written by Natalie Herring and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Zinc Oxide (ZnO) is one of the most extensively studied semiconductors because of its unique properties, namely, its wide band gap (3.37 eV) and high excitation binding energy (60 meV). These properties make ZnO a promising material for uses in a broad range of applications including sensors, catalysis and optoelectronic devices. The presented research covers a broad spectrum of these interesting nanomaterials, from their synthesis and characterization to their use as photocatalyts. A new synthetic approach for producing morphology controlled ZnO nanostructures was developed using microwave irradiation (MWI). The rapid decomposition of zinc acetate in the presence of a mixture of oleic acid (OAC) and oleylamine (OAM) results in the formation of hexagonal ZnO nanopyramids and ZnO rods of varying aspect ratios. The factors that influence the morphology of these ZnO nanostructures were investigated. Using ligand exchange, the ZnO nanostructures can be dispersed in aqueous medium, thus allowing their use as photocatalysts for the degradation of malachite green dye in water. Photocatalytic activity is studied as a function of morphology; and, the ZnO nanorods show enhanced photocatalytic activity for the degradation of the dye compared to hexagonal ZnO nanopyramids. After demonstrating the catalytic activity of these ZnO nanostructures, various ways to enhance photocatalytic activity were studied by modification of this MWI method. Photocatalytic activity is enhanced through band gap modulation and the reduction of electron-hole recombination. Several approaches were studied, which included the incorporation of Au nanoparticles, N-doping of ZnO, supporting ZnO nanostructures on reduced graphene oxide (RGO), and supporting N-doped ZnO on N-doped RGO. ZnO-based nanostructures were studied systematically through the entire process from synthesis and characterization to their use as photocatalysis. This allows for a thorough understanding of the parameters that impact these processes and their unique photocatalytic properties.
Download or read book Semiconductor Photocatalysis written by Wenbin Cao and published by BoD – Books on Demand. This book was released on 2016-08-24 with total page 678 pages. Available in PDF, EPUB and Kindle. Book excerpt: Photocatalysis is a hot topic because it is an environmentally friendly approach toward the conversion of light energy into chemical energy at mild reaction environments. Also, it is well applied in several major areas such as water splitting, bacterial inactivation, and pollutants elimination, which is a possible solution to energy shortage and environmental issues. The fundamental knowledge and the frontier research progress in typical photocatalytic materials, such as TiO2-based and non-TiO2-based photocatalysts, are included in this book. Methods to improve the photocatalytic efficiency and to provide a hint for the rational design of the new photocatalysts are covered.
Download or read book Zinc Oxide Based Nano Materials and Devices written by , Prof. Dr. Ahmed Nahhas and published by BoD – Books on Demand. This book was released on 2019-10-09 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents a review of recent advances in ZnO-based nanomaterials and devices. ZnO as a nanomaterial has gained substantial interest in the research area of wide bandgap semiconductors and is considered to be one of the major candidates for electronic and photonic applications. ZnO has distinguished and interesting electrical and optical properties and is considered to be a potential material in optoelectronic applications such as solar cells, surface acoustic wave devices, and UV emitters. ZnO's unique properties have attracted several researchers to study its electrical and optical properties. As a nanostructured material, ZnO exhibits many advantages for nanodevices. Moreover, it has the ability to absorb the UV radiation.
Download or read book Application of Photoactive Nanomaterials in Degradation of Pollutants written by Roberto Comparelli and published by MDPI. This book was released on 2019-08-27 with total page 134 pages. Available in PDF, EPUB and Kindle. Book excerpt: Photoactive nanomaterials have been receiving increasing attention due to their potential application in the light-driven degradation of water and gas-phase pollutants. However, to exploit the great potential of photoactive materials and access their properties requires fine-tuning of their size/shape-dependent chemical–physical properties, and on the ability to integrate them in photoreactors or to deposit them onto large surfaces. Therefore, the synthetic approach as well as post-synthesis manipulation could strongly affect the final photocatalytic properties of the nanomaterial. The aim of the present Special Issue is to report on the most recent progress towards the application of photoactive nanomaterials and nanomaterial-based coatings in pollutant degradation, paying particular attention to cases close to real application: scalable synthetic approaches to nanocatalysts, preparation of nanocatalyst-based coatings, degradation of real pollutants and bacterial inactivation, and application in building materials.
Download or read book Nanostructured Zinc Oxide written by Kamlendra Awasthi and published by Elsevier. This book was released on 2021-08-10 with total page 781 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nanostructured Zinc Oxide covers the various routes for the synthesis of different types of nanostructured zinc oxide including; 1D (nanorods, nanowires etc.), 2D and 3D (nanosheets, nanoparticles, nanospheres etc.). This comprehensive overview provides readers with a clear understanding of the various parameters controlling morphologies. The book also reviews key properties of ZnO including optical, electronic, thermal, piezoelectric and surface properties and techniques in order to tailor key properties. There is a large emphasis in the book on ZnO nanostructures and their role in optoelectronics. ZnO is very interesting and widely investigated material for a number of applications. This book presents up-to-date information about the ZnO nanostructures-based applications such as gas sensing, pH sensing, photocatalysis, antibacterial activity, drug delivery, and electrodes for optoelectronics. Reviews methods to synthesize, tailor, and characterize 1D, 2D, and 3D zinc oxide nanostructured materials Discusses key properties of zinc oxide nanostructured materials including optical, electronic, thermal, piezoelectric, and surface properties Addresses most relevant zinc oxide applications in optoelectronics such as light-emitting diodes, solar cells, and sensors
Download or read book Multifunctional Oxide Based Materials From Synthesis to Application written by Teofil Jesionowski and published by MDPI. This book was released on 2019-09-03 with total page 204 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book deals with novel aspects and perspectives in metal oxide and hybrid material fabrication. The contributions are mainly focused on the search for a new group of advanced materials with designed physicochemical properties, especially an expanded porous structure and defined surface activity. The proposed technological procedures result in an enhanced activity of the synthesized hybrid materials, which is of great importance when considering their potential fields of application. The use of such materials in different technological disciplines, including aspects associated with environmental protection, allows for the verification of the proposed synthesis method. Thus, it can be stated that those aspects are of interdisciplinary character and may be located at the interface of three scientific disciplines—chemistry, materials science, and engineering—as well as environmental protection. Furthermore, the presented scientific scope is in some way an answer to the continuous demand for such types of materials and opens new perspectives for their practical use
Download or read book Heterogeneous Photocatalysis written by M. Schiavello and published by . This book was released on 1997-10-09 with total page 218 pages. Available in PDF, EPUB and Kindle. Book excerpt: Photocatalysis is a reaction which is accelerated by light while a heterogeneous reaction consists of two phases ( a solid and a liquid for example). Heterogeneous Photocatalysis is a fast developing science which to date has not been fully detailed in a monograph. This title discusses the basic principles of heterogeneous photocatalysis and describes the bulk and surface properties of semiconductors. Applications of various types of photoreactions are described and the problems related to the modeling and design of photoreactors are covered.
Download or read book Handbook of Zinc Oxide and Related Materials written by Zhe Chuan Feng and published by Taylor & Francis. This book was released on 2012-09-26 with total page 447 pages. Available in PDF, EPUB and Kindle. Book excerpt: Through their application in energy-efficient and environmentally friendly devices, zinc oxide (ZnO) and related classes of wide gap semiconductors, including GaN and SiC, are revolutionizing numerous areas, from lighting, energy conversion, photovoltaics, and communications to biotechnology, imaging, and medicine. With an emphasis on engineering a
Download or read book ZnO and TiO2 Based Nanostructures written by Andrea Lamberti and published by MDPI. This book was released on 2018-10-15 with total page 381 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a printed edition of the Special Issue "ZnO and TiO2 Based Nanostructures" that was published in Nanomaterials
Download or read book Study of the Synthesis Machanisms and Optical Properties of ZnO Nanomaterials Obtained by Supercritical Fluids Route written by Evgeniy Ilin and published by . This book was released on 2014 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Zinc oxide (ZnO) is a well-known and intensively studied material for optoelectronic applications in the ultraviolet (UV) spectrum region due to its wide band gap energy - 3.34 eV. However, the UV applications based on nanostructured ZnO present a big challenge due to the small size of the nanostructures i.e. a large surface-to-volume ratio resulting the appearance of the visible emission originated from the surface defects. In the last decades, the progress concerning the fabrication of UV-emitting ZnO nanostructures was carried out through the high temperature gas phase based approach. However, the size and shape control of ZnO nanostructures obtained with this approach is still difficult. Taking into account the state of the art in the optics based on ZnO nanomaterials, this Ph.D. thesis demonstrates the development of new supercritical fluids based approach for the synthesis of ZnO nanostructures with UV-emitting only PL properties. First of all in this thesis, we have developed continuous supercritical set up from micro- up to millifluidic reactor dimension for the synthesis of a larger quantity of UV-emitting ZnO nanocrystals (a gram scale per day). The influence of reactor dimension associated with hydrodynamics on physico-chemical characteristics was investigated. ZnO nanocrystals formation mechanism was studied as a function of the residence time in our continuous supercritical fluids process for the understanding of the nucleation and growth of the nanocrystals. Moreover, ZnO nanocrystals formation mechanism determines UV-emitting properties of this material. The optical properties at room and low temperature were deeply investigated with comparing to the PL emission of several types of ZnO particles and single crystal for the understanding of the nature of UV emission.
Download or read book Design Fabrication and Characterization of Multifunctional Nanomaterials written by Sabu Thomas and published by Elsevier. This book was released on 2021-11-24 with total page 610 pages. Available in PDF, EPUB and Kindle. Book excerpt: Design, Fabrication, and Characterization of Multifunctional Nanomaterials covers major techniques for the design, synthesis, and development of multifunctional nanomaterials. The chapters highlight the main characterization techniques, including X-ray diffraction, scanning electron microscopy, high-resolution transmission electron microscopy, energy dispersive X-ray spectroscopy, and scanning probe microscopy.The book explores major synthesis methods and functional studies, including: Brillouin spectroscopy; Temperature-dependent Raman spectroscopic studies; Magnetic, ferroelectric, and magneto-electric coupling analysis; Organ-on-a-chip methods for testing nanomaterials; Magnetron sputtering techniques; Pulsed laser deposition techniques; Positron annihilation spectroscopy to prove defects in nanomaterials; Electroanalytic techniques. This is an important reference source for materials science students, scientists, and engineers who are looking to increase their understanding of design and fabrication techniques for a range of multifunctional nanomaterials. Explains the major design and fabrication techniques and processes for a range of multifunctional nanomaterials; Demonstrates the design and development of magnetic, ferroelectric, multiferroic, and carbon nanomaterials for electronic applications, energy generation, and storage; Green synthesis techniques and the development of nanofibers and thin films are also emphasized.
Download or read book Metal Oxide Nanostructures written by Daniela Nunes and published by Elsevier. This book was released on 2018-11-01 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt: Metal Oxide Nanostructures: Synthesis, Properties and Applications covers the theoretical and experimental aspects related to design, synthesis, fabrication, processing, structural, morphological, optical and electronic properties on the topic. In addition, it reviews surface functionalization and hybrid materials, focusing on the advantages of these oxide nanostructures. The book concludes with the current and future prospective applications of these materials. Users will find a complete overview of all the important topics related to oxide nanostructures, from the physics of the materials, to its application. Delves into hybrid structured metal oxides and their promising use in the next generation of electronic devices Includes fundamental chapters on synthesis design and the properties of metal oxide nanostructures Provides an in-depth overview of novel applications, including chromogenics, electronics and energy
Download or read book ZnO and Their Hybrid Nano Structures written by Gaurav Sharma and published by Materials Research Forum LLC. This book was released on 2023-06-05 with total page 333 pages. Available in PDF, EPUB and Kindle. Book excerpt: ZnO and its hybrid nanostructures have unique optical, physical and chemical properties. The book covers recent trends in processing techniques and applications. Topics include solar cells, photo-voltaic devices, fuel cells, uv filters, lasers, light-emitting diodes, photo-detectors, spin-tronic devices, magnetic semiconductors, nano-generators, piezotronics, photo-catalytic applications against harmful organic pollutants like dyes, heavy metals, antibiotics, and sensors such as bio sensors, chemical sensors, gas sensors. Keywords: ZnO, Nano ZnO, Point Defects, Magnetic Semiconductors, Hybrid Nanostructures, Cell Applications, Nanoadsorbant for Heavy Metal Removals, Diagnostics, ZnO Nano-Carriers, ZnO Thin Films Fabrication.
Download or read book Synthesis Characterization and Environmental Applications of ZnO Based Nanostructures written by Yangsi Liu and published by . This book was released on 2014 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt: ZnO nanostructures have drawn a great attention from researchers worldwide for their unique chemical, physical, electrical, and optical properties in the recent years. One of the biggest advantages of ZnO is that it can be synthesized by a variety of methods, which also results in the richest family of its nanostructures with various dimensions among all materials. As an important metal oxide semiconductor, the nanostructured ZnO materials have been considered as the promising building blocks for nanodevices for a broad range of applications in catalysis, electronics and photonics. Therefore, realizing ZnO based materials with desired nanostructure and enhanced performance is essential in the research and applications of ZnO. The research reported in this thesis is mainly focused on the development of ZnO based nanostructures by facile and economic approaches, the analysis of their compositional, structural, and functional properties, the understanding of growth and behaviour mechanism of these nanostructures, and the study of their performance in environmental applications. Several characterization techniques, such as scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), high resolution transmission electron microscope (HRTEM), Raman scattering, photoluminescence (PL) emission and Ultraviolet-visible light (UV-vis) spectra, have been applied in this research to verify the morphology, microstructure, chemical composition, growth process, crystal structure, defects and optical properties of various ZnO based nanostructures. One dimensional (1D) ZnO nanorod arrays were grown on glass substrates with ZnO seeds via a low temperature and ambient atmosphere hydrothermal method. The concentration of precursors can change the aspect ratio, surface roughness and the band gap energy of the nanorods. They were applied in the degradation of estrone, and the hydrogen peroxide (H2O2) formed during photocatalysis process was detected by fluorescence analysis. The results revealed that the ZnO nanorod array produced from 25 mM reactants had the highest aspect ratio, the largest surface roughness, the lowest band gap energy, and a suitable rod gap distance, favouring the UV light utilization, photocatalytic degradation and H2O2 generation. The pH value of the solution has a significant effect on the growth behaviour and morphology of ZnO nanorods. The crystal size and the alignment of ZnO nanorods grown from neutral (pH = 7) and acid (pH = 5) conditions were distinctly different although both of them had hexagonal wurtzite phase. The pH can adjust the chemical reactions direction, influence the extent of nucleation and crystal growth by varying the degree of supersaturation, and also tailor the distribution and orientation of ZnO nuclei, thereby having a great effect on the crystal size and the alignment of ZnO nanorods. Complex three dimensional (3D) ZnO trunk-branch nanostructures immobilized on glass substrates were achieved by a multi-step growth method without any capping agents. The process included the magnetron sputtering and hydrothermal growth. Both the large primal trunks and small branches were single crystal grown along [0001] direction. This hierarchical ZnO nanostructures with additional active surface, improved light harvesting and a large amount of defects exhibited better photocatalytic efficiency in degradation of rhodamine B (RhB) than nonbranched samples. ZnO nanorod arrays were combined with Ag to study their photocatalytic activity under visible light. The Ag/ZnO heterostructures were realized by photoreduction in various reducing mediums. In the air, only a small amount of Ag nanoribbons was reduced. Ag nanosheets and nanoparticles produced in water to form a nano (sheet-rod-particle) multilevel structure with the ZnO nanorods. A large amount of Ag nanoclusters were embedded in the ZnO nanorod arrays in the water mixed with ethanol. The Ag component stimulated the surface phonon resonance, which is the root cause for the visible light driven photocatalysis. The effect of quantity and dispersion of Ag nanostructures on the optical properties, and the photocatalytic behaviour of Ag/ZnO heterostructures was investigated. Time-affected wettability was compared among the TiO2/ZnO nanocomposite, ZnO/ZnO bi-level nanostructure and ZnO nanorod arrays by measuring the water contact angles on their surfaces. In ambient conditions, their surfaces transformed spontaneously from hydrophilic to hydrophobic during a long time storage. The replacement of initial surface hydroxyl groups by oxygen atoms and the adsorption of organic contaminants in the air would be the main reasons for such a conversion. The influence of morphological features and surface chemical components on the wettability change rate was discussed. In the last part of this thesis, conclusions and future works are addressed according to the synthesis, characterization and application results.
Download or read book Zinc Oxide written by Carmen Galvan and published by . This book was released on 2020 with total page 290 pages. Available in PDF, EPUB and Kindle. Book excerpt: "In Zinc Oxide: Production, Properties and Applications, the authors first provide a summary of the natural sources available for the synthesis of zinc oxide nanoparticles, enlisting some plant-mediated synthesized zinc oxide nanoparticles showing promising antimicrobial, antioxidant, cytotoxic and photocatalytic properties. Important technological opportunities and challenges emphasizing the electrical and optoelectronic features of elongated zinc oxide nanoparticle nanosystems are reviewed. The various nonlinear optical phenomenon observed in zinc oxide thin film, including nonlinear absorption, nonlinear refraction, nonlinear scattering and harmonic generations are introduced. Selected literature on the use of zinc oxide nanoparticles for the immobilization of enzymes is reviewed, as well as the use of zinc oxide nanoparticle/enzyme systems in the fabrication of biosensors. The authors explore transition metal doped zinc oxide nanoparticles for a wide range of catalytic organic reactions, further exploring their catalytic applications for organic transformations at mild reaction conditions. The basic concepts behind the development of nanostructured zinc oxide nanoparticles, including the solid state reaction, hydrothermal method, solvothermal method and co-precipitation method are discussed. Lastly, a facile, eco-friendly synthesis of zinc oxide nanoparticles using the peel extract of Musa paradisiaca L, Punica granatum L, and Citrus reticulata Blanco as bioreducing agent is reported"--
Download or read book Handbook of Greener Synthesis of Nanomaterials and Compounds written by Boris I. Kharisov and published by Elsevier. This book was released on 2021-04-03 with total page 976 pages. Available in PDF, EPUB and Kindle. Book excerpt: Modern techniques to produce nanoparticles, nanomaterials, and nanocomposites are based on approaches that frequently involve high costs, inefficiencies, and negative environmental impacts. As such, there has been a real drive to develop and apply approaches that are more efficient and benign. The Handbook of Greener Synthesis of Nanomaterials and Compounds provides a comprehensive review of developments in this field, combining foundational green and nano-chemistry with the key information researchers need to assess, select and apply the most appropriate green synthesis approaches to their own work. Volume 1: Fundamental Principles and Methods provides a clear introduction to the fundamentals of green synthesis that places synthesis in the context of green chemistry. Beginning with a discussion of key greener physical and chemical methods for synthesis, including ultrasound, microwave and mechanochemistry methods, the book goes on to explore biological methods, including biosynthesis, green nanoformation, and virus-assisted methods. Discusses synthesis in the context of the principles of green chemistry Highlights both traditional and innovative technologies for the synthesis of nanomaterials and related composites under green chemistry conditions Reflects on the current and potential applications of natural products chemistry in synthesis
Download or read book Handbook of Green and Sustainable Nanotechnology written by Uma Shanker and published by Springer Nature. This book was released on 2023-05-27 with total page 2759 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Handbook of Green and Sustainable Nanotechnology presents sustainable and green technologies for the development of products and processes which are environmental friendly, economically sustainable, safe, energy-efficient, decrease waste and diminish greenhouse gas emissions. It provides the overall spectrum of fundamentals, development and applications of sustainable and green technologies. Topics such as legal, health and safety issues are discussed as well. The book elucidates paths to real time utilization of green and sustainable nanotechnology at commercial scale.
