Download or read book Development of Nickel Complexes as Photocatalysts for Hydrogen Evolution written by and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis and Characterization of Nickel Thiolate Complexes for Photocatalytic Hydrogen Evolution written by 朱哲民 and published by . This book was released on 2017 with total page 118 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Homogeneous Photocatalysis written by M. Chanon and published by John Wiley & Sons. This book was released on 1997-03-06 with total page 440 pages. Available in PDF, EPUB and Kindle. Book excerpt: Photocatalysis and related processes occupy a strategic position for the future of photochemistry. This volume provides an introduction to basic concepts and explains how applications work at the molecular level.
Download or read book First row Transition Metal Coordination Compounds for the Electrocatalytic Generation of Hydrogen from Organic and Aqueous Solutions written by Patrick M. Crossland and published by . This book was released on 2015 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt: The development of stable proton reduction catalysts is imperative due to their importance as a source of a carbon-neutral fuel. A cobalt-salen complex with electron withdrawing groups was synthesized. This complex generated protons from organic solutions at a 190 mV overpotential with a kobs of 42000 M-2s-1, and a corresponding turnover frequency of 420 s-1. This is one of the lowest overpotentials reported for a cobalt proton reduction catalyst. While insoluble in water, an experiment where water was added to an electrochemical cell showed a 20% increase in catalytic activity. This indicates that cobalt-salen complexes could be highly active in aqueous solutions. Developing first row transition metal complexes for electro- and photocatalytic hydrogen evolution is of great interest. A photocatalyst for proton reduction could be incorporated into an artificial photosynthesis device to generate hydrogen gas as a solar fuel. Nickel was complexed with the H3ttfasbz ligand, which is known to be redox active.35 In order to assess its catalytic ability electrochemical tests, including proton concentration experiments, and catalyst concentration experiments were performed. These tests showed the nickel complex to be highly active for hydrogen reduction at a cathodic potential (-1.37 V vs. SCE). Due to the high overpotential of this complex, it was integrated into a photocatalytic system with fluorescein as a chromophore.
Download or read book Green Photocatalytic Semiconductors written by Seema Garg and published by Springer Nature. This book was released on 2021-09-20 with total page 855 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book comprises a detailed overview on the role of photocatalysts for environmental remediation, hydrogen production and carbon dioxide reduction. Effective ways to enhance the photocatalytic activity of the material via doping, hybrid material, laser light and nanocomposites have been discussed in this book. The book also further elaborates the role of metal nanoparticles, rare earth doping, sensitizers, surface oxygen vacancy, interface engineering and band gap engineering for enhancing the photocatalytic activity. An approach to recover the photocatalytic material via immobilization is also presented. This book brings to light much of the recent research in the development of such semiconductor photocatalytic systems. The book will thus be of relevance to researchers in the field of: material science, environmental science & technology, photocatalytic applications, newer methods of energy generation & conversion and industrial applications.
Download or read book Ligand Participation in Energy Storage Electrocatalysis and Photocatalysis written by Andrew Gerard Maher and published by . This book was released on 2018 with total page 249 pages. Available in PDF, EPUB and Kindle. Book excerpt: The electrochemical or photochemical production of fuels using energy from the sun is an attractive approach for storing solar energy. However, the development of efficient and inexpensive catalysts is necessary to facilitate these reactions. While a number of molecular catalysts do exist for this purpose, a lack of deep understanding of how they operate on a mechanistic level impedes their optimization and rational design. This thesis addresses the key mechanistic issue of ligand participation during energy storage catalysis using electrochemical, spectroscopic (both steady-state and time-resolved), synthetic, and computational techniques. The thesis begins by investigating the reactivity of nickel porphyrins during the electrocatalytic generation of hydrogen from acid. Rather than forming a traditional metal-hydride intermediate, nickel porphyrins are found to be protonated on the macrocycle ligand to first form a phlorin intermediate and ultimately a doubly-hydrogenated isobacteriochlorin species. The Ni isobacteriochlorin serves as the active hydrogen evolution catalyst, with ring reduction of the ligand necessary to drive metal-hydride formation. A synthetic cobalt chlorin in which the ring reduction is structurally enforced is then investigated. The cobalt chlorin also generates hydrogen electrochemically, and a mechanistic study reveals a greater intrinsic activity than metal porphyrins when compared at low overpotentials, likely due to an increased hydricity imparted by the highly-reduced ligand. The thesis then turns to the role of direct ligand reactivity in enhancing the photoreactivity of monomeric nickel complexes. Transient absorption (TA) spectroscopic studies reveal that the triphenylphosphine ligand of Ni halide hydrogen-evolving photocatalysts serves as the photosensitizer and as a redox mediator in what is determined to be a tandem cycle. TA also demonstrates the role of halogen-arene charge transfer intermediates in increasing the quantum yield of halogen photoelimination by Ni(III) trichloride complexes containing bidendate phosphine ligands that include aryl groups. The thesis concludes with an examination of the electron transfer kinetics of a soluble form of peroxide dianion stabilized by a hydrogen-bonding cryptand ligand. Ultrafast oxidation of the peroxide using photosensitizers of varying oxidizing power allows for measurement of the inner-sphere reorganization energy, which is dominated by the contraction of the O-O bond.
Download or read book Energy Resources through Photochemistry and Catalysis written by Michael Gratzel and published by Elsevier. This book was released on 2012-12-02 with total page 588 pages. Available in PDF, EPUB and Kindle. Book excerpt: Energy Resources through Photochemistry and Catalysis reviews the state of the art in the development of energy conversion devices based on catalytic and photochemical reactions. The focus is on catalysis of redox reactions and their application to the photocleavage of water, reduction of carbon dioxide, and fixation of nitrogen. Some fundamental aspects of catalysis as it relates to processes of light energy harvesting and charge separation in photochemical or photoelectrochemical conversion systems are also discussed. This monograph is comprised of 16 chapters covering light-induced redox reactions and reaction dynamics in organized assemblies such as micelles, colloidal metals, or semiconductors, together with strategies for molecular engineering of artificial photosynthetic devices. The principles of electrochemical conversion of light energy via semiconductor electrodes or semiconducting particles are also considered. Furthermore, thermodynamic characteristics for some reactions that can be utilized for storage of solar energy in the form of chemical energy are examined. The remaining chapters look at the role of porphyrins in natural and artificial photosynthesis; the use of semiconductor powders and particulate systems for photocatalysis and photosynthesis; and hydrogen-generating solar cells based on platinum-group metal activated photocathodes. This text will be a useful resource for scientists and policymakers concerned with finding alternative sources of energy.
Download or read book Current Developments in Photocatalysis and Photocatalytic Materials written by Xinchen Wang and published by Elsevier. This book was released on 2019-11-29 with total page 568 pages. Available in PDF, EPUB and Kindle. Book excerpt: Photocatalytic materials can improve the efficiency and sustainability of processes and offer novel ways to address issues across a wide range of fields—from sustainable chemistry and energy production to environmental remediation. Current Developments in Photocatalysis and Photocatalytic Materials provides an overview of the latest advances in this field, offering insight into the chemistry and activity of the latest generation of photocatalytic materials.After an introduction to photocatalysis and photocatalytic materials, this book goes on to outline a wide selection of photocatalytic materials, not only covering typical metal oxide photocatalysts such as TiO2 but also exploring newly developed organic semiconducting photocatalysts, such as g-C3N4.Drawing on the experience of an expert team of contributors, Current Developments in Photocatalysis and Photocatalytic Materials highlights the new horizons of photocatalysis, in which photocatalytic materials will come to play an important role in our day-to-day lives. Reviews developments in both organic- and inorganic-based materials for use in photocatalysis Presents the fundamental chemistry and activity of a broad range of key photocatalytic materials, including both typical and novel materials Highlights the role photocatalytic materials can play in sustainable applications
Download or read book Novel strategies to design and construct efficient semiconductor based photocatalyst for enhancing photocatalytic hydrogen evolution and nitrogen fixation under sunlight irradiation written by Manh Hiep Vu and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Résumé en anglais
Download or read book Photophysics Photochemical and Substitution Reactions written by Satyen Saha and published by BoD – Books on Demand. This book was released on 2021-06-30 with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book represents a unique blend of topics covering photon-initiated reactions to substitution reactions. Additionally, several fantastic chapters on the photophysics of popular dyes and their applications make the book interesting for researchers working on photon-initiated physical and chemical processes.
Download or read book Photocatalytic Hydrogen Evolution written by Misook Kang and published by MDPI. This book was released on 2020-06-17 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt: Energy crises and global warming pose serious challenges to researchers in their attempt to develop a sustainable society for the future. Solar energy conversion is a remarkable, clean, and sustainable way to nullify the effects of fossil fuels. The findings of photocatalytic hydrogen production (PCHP) by Fujishima and Honda propose that “water will be the coal for the future”. Hydrogen is a carbon-free clean fuel with a high specific energy of combustion. Titanium oxide (TiO2), graphitic-carbon nitride (g-C3N4) and cadmium sulfide (CdS) are three pillars of water splitting photocatalysts owing to their superior electronic and optical properties. Tremendous research efforts have been made in recent years to fabricate visible or solar-light, active photocatalysts. The significant features of various oxide, sulfide, and carbon based photocatalysts for cost-effective hydrogen production are presented in this Special Issue. The insights of sacrificial agents on the hydrogen production efficiency of catalysts are also presented in this issue.
Download or read book CO2 Hydrogenation Catalysis written by Yuichiro Himeda and published by John Wiley & Sons. This book was released on 2021-06-28 with total page 322 pages. Available in PDF, EPUB and Kindle. Book excerpt: A guide to the effective catalysts and latest advances in CO2 conversion in chemicals and fuels Carbon dioxide hydrogenation is one of the most promising and economic techniques to utilize CO2 emissions to produce value-added chemicals. With contributions from an international team of experts on the topic, CO2 Hydrogenation Catalysis offers a comprehensive review of the most recent developments in the catalytic hydrogenation of carbon dioxide to formic acid/formate, methanol, methane, and C2+ products. The book explores the electroreduction of carbon dioxide and contains an overview on hydrogen production from formic acid and methanol. With a practical review of the advances and challenges in future CO2 hydrogenation research, the book provides an important guide for researchers in academia and industry working in the field of catalysis, organometallic chemistry, green and sustainable chemistry, as well as energy conversion and storage. This important book: Offers a unique review of effective catalysts and the latest advances in CO2 conversion Explores how to utilize CO2 emissions to produce value-added chemicals and fuels such as methanol, olefins, gasoline, aromatics Includes the latest research in homogeneous and heterogeneous catalysis as well as electrocatalysis Highlights advances and challenges for future investigation Written for chemists, catalytic chemists, electrochemists, chemists in industry, and chemical engineers, CO2 Hydrogenation Catalysis offers a comprehensive resource to understanding how CO2 emissions can create value-added chemicals.
Download or read book The Electro and Photocatalytic Activity of a Ni NNSS Schiff Base Complex for Hydrogen Generation written by Catherine F. Wise and published by . This book was released on 2015 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt: Developing an efficient and cost-effective method of harvesting solar energy will greatly help to solve the global energy crisis, as the sun provides more energy in an hour than the world uses in an entire year. One of the most promising solutions to this problem is artificial photosynthesis, a process that mimics photosynthesis in plants to store energy in the chemical bonds of hydrogen gas. In order to develop systems for artificial photosynthesis, stable and active catalysts that can reduce protons must be identified. The new complexes, [NiII(Httfasbz)] and [NiII(L2)] (where L2 = (2E, 2'E)-dibenzyl 2,2'-(1,2-diphenylethane-1,2-diylidene)bis(hydrazinecarbodithioate)), were characterized and then analyzed as electrocatalysts for hydrogen generation. Both were found to be active catalysts for electrochemical proton reduction, with [NiII(Httfasbz)] giving an ic/ip of 6.4 and [NiII(L2)] giving an ic/ip of 42.9 in solutions of CH3CN. [NiII(Httfasbz)] was further studied in a system for photochemical hydrogen generation. As a photocatalyst, [NiII(Httfasbz)] is both active and stable, producing TONs over 1100 after 18 hours and continuing to generate hydrogen for over 70 hours.
Download or read book Visible Light Active Photocatalysis written by Srabanti Ghosh and published by John Wiley & Sons. This book was released on 2018-06-11 with total page 624 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive and timely overview of this important and hot topic, with special emphasis placed on environmental applications and the potential for solar light harvesting. Following introductory chapters on environmental photocatalysis, water splitting, and applications in synthetic chemistry, further chapters focus on the synthesis and design of photocatalysts, solar energy conversion, and such environmental aspects as the removal of water pollutants, photocatalytic conversion of CO2. Besides metal oxide-based photocatalysts, the authors cover other relevant material classes including carbon-based nanomaterials and novel hybrid materials. Chapters on mechanistic aspects, computational modeling of photocatalysis and Challenges and perspectives of solar reactor design for industrial applications complete this unique survey of the subject. With its in-depth discussions ranging from a comprehensive understanding to the engineering of materials and applied devices, this is an invaluable resource for a range of disciplines.
Download or read book Evaluation of Micro and Nanostructured Nickel Oxide as Photocatalysts for Hydrogen Evolution from Water written by Jorie Marie Fields and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Nickel (II) oxide (NiO) is a p-type semiconductor that has been commonly used as a co-catalyst for photocatalytic water-splitting. Here, NiO is investigated for its optical properties, electrochemical photo-onsets and photo-currents, and photocatalytic activity for hydrogen evolution in 20% aqueous methanol. Nano NiO (10 nm thick, 50-100 nm wide disks) and bulk NiO (0.05-2 m) were synthesized and platinated by photodeposition (1 mol %); the crystal structures were verified by XRD and TEM. We show that NiO is photocatalytically active for H2 evolution from water in the presence of the electron donor methanol. Platinated nano NiO had the highest rate of oxygen evolution (162.3 mol H2 g−1 hr−1, followed by nano NiO (43.1 mol H2 g−1 hr−1, platinated bulk NiO (4.0 mol H2 g−1 hr−1), and bulk NiO (2.0 mol H2 g−1 hr−1). Overall, these findings show the first use of NiO as a water-splitting photocatalyst.
Download or read book Introduction to Photocatalysis written by Yoshio Nosaka and published by Royal Society of Chemistry. This book was released on 2019-03-07 with total page 272 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presenting the basic science of semiconductor photocatalysis together with the various practical applications, this textbook is ideal for graduate students. It covers fundamental principles and applicable techniques of light, solid state physics, electrochemistry, reaction kinetics, and materials processing. A solid understanding of semiconductor photoelectrochemistry is developed through discussing the basic properties of a representative photocatalytic material, TiO2; the basic science of the light absorption phenomenon and the application to the powder suspension useful for the photocatalytic research; and the electronic state of semiconductors. Following this, the textbook moves on to explore photoelectrochemistry; the mechanism and kinetic analysis of photocatalytic reactions; typical fabrication methods of common photocatalysts and the factors for improving photocatalytic activity; and evaluation methods of photocatalytic activity. The textbook concludes by looking at the future prospects of the applications of photocatalysis. This introductory textbook provides a foundation in photocatalysis to supplement graduate courses in catalysis, environmental science, materials science and chemical engineering.
Download or read book Redox Active Ligands written by Marine Desage-El Murr and published by John Wiley & Sons. This book was released on 2024-01-31 with total page 373 pages. Available in PDF, EPUB and Kindle. Book excerpt: Redox-Active Ligands Authoritative resource showcasing a new family of ligands that can lead to better catalysts and promising applications in organic synthesis Redox-Active Ligands gives a comprehensive overview of the unique features of redox-active ligands, describing their structure and synthesis, the characterization of their coordination complexes, and important applications in homogeneous catalysis. The work reflects the diversity of the subject by including ongoing research spanning coordination chemistry, organometallic chemistry, bioinspired catalysis, proton and electron transfer, and the ability of such ligands to interact with early and late transition metals, lanthanides, and actinides. The book is divided into three parts, devoted to introduction and concepts, applications, and case studies. After the introduction on key concepts related to the field, and the different types of ligands and complexes in which ligand-centered redox activity is commonly observed, mechanistic and computational studies are described. The second part focuses on catalytic applications of redox-active complexes, including examples from radical transformations, coordination chemistry and organic synthesis. Finally, case studies of redox-active guanidine ligands, and of lanthanides and actinides are presented. Other specific sample topics covered include: An overview of the electronic features of redox-active ligands, covering their historical perspective and biological background The versatility and mode of action of redox-active ligands, which sets them apart from more classic and tunable ligands such as phosphines or N-heterocyclic carbenes Preparation and catalytic applications of complexes of stable N-aryl radicals Metal complexes with redox-active ligands in H+/e- transfer transformations By providing up-to-date information on important concepts and applications, Redox-Active Ligands is an essential reading for researchers working in organometallic and coordination chemistry, catalysis, organic synthesis, and (bio)inorganic chemistry, as well as newcomers to the field.
