Energy Production and Storage E-Book

• Herausgeber: John Wiley & Sons
• Kategorie: Wissenschaft und neue Technologien
• Serie: EIC Books
• Sprache: Englisch

Seitenzahl: 1350

Veröffentlichungsjahr: 2013

Beschreibung

Energy production and storage are central problems for our time. In principle, abundant energy is available from the sun to run the earth in a sustainable way. Solar energy can be directly harnessed by agricultural and photovoltaic means, but the sheer scale of the energy demand poses severe challenges, for example any major competition between biomass production and food production would simply transfer scarcity from energy to food. Indirect use of solar energy in the form of wind looks also promising, especially for those regions not blessed with abundant sunlight. Other modes such as tidal and wave energy may well become important niche players.

Inorganic chemistry plays a decisive role in the development of new energy technologies and   this Volume covers some promising modes of alternative energy production and storage that minimize the atmospheric burden of fossil-derived carbon monoxide. No one production or storage mode is likely to dominate, at least at first, and numerous possibilities need to be explored to compare their technical feasibility and economics. This provides the context for a broad exploration of novel ideas that we are likely to see in future years as the field expands.

This Volume covers a wide range of topics, such as: - Water splitting, only water is a sufficiently cheap and abundant electron source for global exploitation; - Energy conversion by photosynthesis; - Molecular catalysts for water splitting; - Thermochemical water splitting; - Photocatalytic hydrogen production; - Artificial photosynthesis, progress of the Swedish Consortium; - Hydrogen economy; - Reduction of carbon dioxide to useful fuels; - Conversion of methane to methanol; - Dye sensitized solar cells; - Photoinitiated electron transfer in fuel cells; - Proton exchange membranes for fuel cells; - Intermediate temperature solid oxide fuel cells; - Direct Ethanol fuel cells; - Molecular catalysis for fuel cells; - Enzymes and microbes in fuel cells; - Li-Ion batteries; - Magic Angle Spinning NMR studies of battery materials; Supercapacitors and electrode materials.

About EIC Books

The Encyclopedia of Inorganic Chemistry (EIC) has proved to be one of the defining standards in inorganic chemistry, and most chemistry libraries around the world have access either to the first or second print edition, or to the online version. Many readers, however, prefer to have more concise thematic volumes, targeted to their specific area of interest. This feedback from EIC readers has encouraged the Editors to plan a series of EIC Books, focusing on topics of current interest. They will appear on a regular basis, and will feature leading scholars in their fields. Like the Encyclopedia, EIC Books aim to provide both the starting research student and the confirmed research worker with a critical distillation of the leading concepts in inorganic and bioinorganic chemistry, and provide a structured entry into the fields covered.

This volume is also available as part of Encyclopedia of Inorganic Chemistry, 5 Volume Set.

This set combines all volumes published as EIC Books from 2007 to 2010, representing areas of key developments in the field of inorganic chemistry published in the Encyclopedia of Inorganic Chemistry. Find out more.

Leseprobe

EIC Books

Application of Physical Methods to Inorganic and Bioinorganic ChemistryEdited by Robert A. Scott and Charles M. LukehartISBN 978-0-470-03217-6

Nanomaterials: Inorganic and Bioinorganic PerspectivesEdited by Charles M. Lukehart and Robert A. ScottISBN 978-0-470-51644-7

Computational Inorganic and Bioinorganic ChemistryEdited by Edward I. Solomon, R. Bruce King and Robert A. ScottISBN 978-0-470-69997-3

Radionuclides in the EnvironmentEdited by David A. AtwoodISBN 978-0-470-71434-8

Energy Production and StorageRobert H. CrabtreeISBN 978-0-470-74986-9

Encyclopedia of Inorganic Chemistry

In 1994 John Wiley & Sons published the Encyclopedia of Inorganic Chemistry (EIC). This 8-volume work was well received by the community, and has become a standard publication in all libraries serving the inorganic, coordination chemistry, organometallic and bioinorganic communities. The 10-volume Second Edition of the Encyclopedia was published in print in 2005, and online in 2006, on the major reference platform Wiley Online Library. The online edition is regularly updated and expanded. For more information see:

http://www.wileyonlinelibrary/ref/eic

This edition first published 2010© 2010 John Wiley & Sons Ltd

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The right of the authors to be identified as the authors of this work has been asserted in accordance with the Copyright, Designs and Patents Act 1988.

All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, except as permitted by the UK Copyright, Designs and Patents Act 1988, without the prior permission of the publisher.

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Front cover image credit (back image): This figure was published in the article ‘Green electricity production with living plants and bacteria in a fuel cell’, Int. J. Energy Res., 2008, 32, 870–876 © John Wiley & Sons, Ltd, 2008.

Library of Congress Cataloging-in-Publication Data

Energy production and storage : inorganic chemical strategies for a warming world / editor, Robert H. Crabtree.

     p. cm.

Includes bibliographical references and index.

     ISBN 978-0-470-74986-9 (cloth: alk. paper)

1. Hydrogen as fuel--Research. 2. Water resources development. 3. Renewable energy sources. 4. Environmental chemistry. 5. Carbon sequestration. I. Crabtree, Robert H., 1948-

     TP359.H8E54 2010

     621.042--dc22

2010025736

A catalogue record for this book is available from the British Library.

ISBN-13: 978-0-470-74986-9

Set in 9½ / 11½ pt TimesNewRomanPS by Laserwords (Private) Limited, Chennai, India. Printed and bound in Singapore by Markono Print Media Pte Ltd.

Encyclopedia of Inorganic Chemistry

Editorial Board

Editor-in-Chief

Robert H. CrabtreeYale University, New Haven, CT, USA

Section Editors

David A. AtwoodUniversity of Kentucky, Lexington, KY, USA

R. Bruce KingUniversity of Georgia, Athens, GA, USA

Charles M. LukehartVanderbilt University, Nashville, TN, USA

Robert A. ScottUniversity of Georgia, Athens, GA, USA

International Advisory Board

Michael BruceAdelaide, Australia

Fausto CalderazzoPisa, Italy

Tristram ChiversCalgary, Canada

Odile EisensteinMontpellier, France

C. David GarnerNottingham, UK

Malcolm GreenOxford, UK

Wolfgang HerrmannMunich, Germany

Jean-Marie LehnStrasbourg, France

François MatheyUniversity of California Riverside, CA, USA

Akira NakamuraOsaka, Japan

Jan ReedijkLeiden, The Netherlands

Vivian YamHong Kong

Contents

Contributors

Series Preface

Volume Preface

PART 1: ENERGY PRODUCTION

H2 Production from RenewablesRufino M. Navarro, M. Cruz Sanchez-Sanchez, M. Consuelo Alvarez-Galvan, Jose Luis G. Fierro and Saeed M. Al-Zaharani

Energy Conversion in PhotosynthesisGözde Ulas and Gary W. Brudvig

Molecular Catalysts for Oxygen Production from WaterAntoni Llobet and Sophie Romain

Dye-Sensitized Solar Cells: an OverviewLuísa Andrade, Helena Aguilar Ribeiro and Adélio Mendes

Enzymes and Microbes for Energy Production by Fuel CellsFrédéric Barrière

Proton Exchange Membranes for Fuel CellsRam Devanathan

Methane-to-Methanol ConversionBrian G. Hashiguchi, Claas H. Hövelmann, Steven M. Bischof, Kapil S. Lokare, Chin Hin Leung and Roy A. Periana

Photocatalytic Hydrogen Production from WaterShamindri M. Arachchige and Karen J. Brewer

Intermediate-Temperature Solid Oxide Fuel CellsAlan Atkinson, John Kilner, Stephen Skinner, Nigel P. Brandon and Dan J. L. Brett

Some Computational Challenges in Energy ResearchVictor S. Batista

Toward Solar Fuels Using a Biomimetic Approach: Progress in the Swedish Consortium for Artificial PhotosynthesisSascha Ott, Stenbjörn Styring, Leif Hammarström and Olof Johansson

Direct Ethanol Fuel CellsZhi Wen Chia and Jim Yang Lee

Molecular Catalysis for Fuel CellsKenichi Oyaizu

Recent Advances in Photo-Initiated Electron-Transfer at the Interface between Anatase TiO2 Nanocrystallites and Transition-Metal Polypyridyl CompoundsShane Ardo and Gerald J. Meyer

Electrochemical and Photoelectrochemical Conversion of CO2 to AlcoholsRobert H. Crabtree

PART 2: ENERGY STORAGE

Hydrogen EconomyStephen A. Wells, Asel Sartbaeva, Vladimir L. Kuznetsov and Peter P. Edwards

Thermal Stability of Lithium Ion Battery ElectrolytesBrett L. Lucht, Tippawan Markmaitree and Li Yang

Supercapacitors: Electrode Materials AspectsLi Li Zhang, Zhibin Lei, Jintao Zhang, Xiaoning Tian and Xiu Song Zhao

Thermochemical Water-SplittingAli T-Raissi

Lithium Ion Batteries for Transportation and Electrical Energy Storage Applications: Nuclear Magnetic Resonance Studies of Structure and FunctionJordi Cabana and Clare P. Grey

Index

Contributors

M. Consuelo Alvarez-Galvan

Institute of Catalysis and Petrochemistry, CSIC, Cantoblanco, Madrid, Spain

•  H

2

Production from Renewables

Luísa Andrade

Universidade do Porto, Porto, Portugal

•  Dye-Sensitized Solar Cells: an Overview

Shamindri M. Arachchige

Virginia Polytechnic Institute and State University, Blacksburg, VA, USA

•  Photocatalytic Hydrogen Production from Water

Shane Ardo

Johns Hopkins University, Baltimore, MD, USA

•  Recent Advances in Photo-Initiated Electron-Transfer at the Interface between Anatase TiO

2

Nanocrystallites and Transition-Metal Polypyridyl Compounds

Alan Atkinson

Imperial College London, London, UK

•  Intermediate-Temperature Solid Oxide Fuel Cells

Saeed M. Al-Zaharani

King Saud University, Riyadh, Saudi Arabia

•  H

2

Production from Renewables

Frédéric Barrière

Université de Rennes 1, France

•  Enzymes and Microbes for Energy Production by Fuel Cells

Victor S. Batista

Yale University, New Haven, CT, USA

•  Some Computational Challenges in Energy Research

Steven M. Bischof

The Scripps Research Institute, Jupiter, FL, USA

•  Methane-to-Methanol Conversion

Nigel P. Brandon

Imperial College London, London, UK

•  Intermediate-Temperature Solid Oxide Fuel Cells

Dan J. L. Brett

Imperial College London and University College London, London, UK

•  Intermediate-Temperature Solid Oxide Fuel Cells

Karen J. Brewer

Virginia Polytechnic Institute and State University, Blacksburg, VA, USA

•  Photocatalytic Hydrogen Production from Water

Gary W. Brudvig

Yale University, New Haven, CT, USA

•  Energy Conversion in Photosynthesis

Jordi Cabana

Lawrence Berkeley National Laboratory, Berkeley, CA, USA

•  Lithium Ion Batteries for Transportation and Electrical Energy Storage Applications: Nuclear Magnetic Resonance Studies of Structure and Function

Zhi Wen Chia

National University of Singapore, Singapore

•  Direct Ethanol Fuel Cells

Robert H. Crabtree

Yale University, New Haven, CT, USA

•  Electrochemical and Photoelectrochemical Conversion of CO

2

to Alcohols

Ram Devanathan

Pacific Northwest National Laboratory, Richland, WA, USA

•  Proton Exchange Membranes for Fuel Cells

Peter P. Edwards

University of Oxford, Oxford, UK

•  Hydrogen Economy

Jose Luis G. Fierro

Institute of Catalysis and Petrochemistry, CSIC, Cantoblanco, Madrid, Spain

•  H

2

Production from Renewables

Clare P. Grey

Stony Brook University, Stony Brook, NY, USA and University of Cambridge, Cambridge, UK

•  Lithium Ion Batteries for Transportation and Electrical Energy Storage Applications: Nuclear Magnetic Resonance Studies of Structure and Function

Leif Hammarström

Uppsala University, Uppsala, Sweden

•  Toward Solar Fuels Using a Biomimetic Approach: Progress in the Swedish Consortium for Artificial Photosynthesis

Brian G. Hashiguchi

The Scripps Research Institute, Jupiter, FL, USA

•  Methane-to-Methanol Conversion

Claas H. Hövelmann

The Scripps Research Institute, Jupiter, FL, USA

•  Methane-to-Methanol Conversion

Olof Johansson

Uppsala University, Uppsala, Sweden

•  Toward Solar Fuels Using a Biomimetic Approach: Progress in the Swedish Consortium for Artificial Photosynthesis

John Kilner

Imperial College London, London, UK

•  Intermediate-Temperature Solid Oxide Fuel Cells

Vladimir L. Kuznetsov

University of Oxford, Oxford, UK

•  Hydrogen Economy

Jim Yang Lee

National University of Singapore, Singapore

•  Direct Ethanol Fuel Cells

Zhibin Lei

National University of Singapore, Singapore

•  Supercapacitors: Electrode Materials Aspects

Chin Hin Leung

The Scripps Research Institute, Jupiter, FL, USA

•  Methane-to-Methanol Conversion

Antoni Llobet

Institute of Chemical Research of Catalonia (ICIQ) and Universitat Autònoma de Barcelona, Barcelona, Spain

•  Molecular Catalysts for Oxygen Production from Water

Kapil S. Lokare

The Scripps Research Institute, Jupiter, FL, USA

•  Methane-to-Methanol Conversion

Brett L. Lucht

University of Rhode Island, Kingston, RI, USA

•  Thermal Stability of Lithium Ion Battery Electrolytes

Tippawan Markmaitree

University of Rhode Island, Kingston, RI, USA

•  Thermal Stability of Lithium Ion Battery Electrolytes

Adélio Mendes

Universidade do Porto, Porto, Portugal

•  Dye-Sensitized Solar Cells: an Overview

Gerald J. Meyer

Johns Hopkins University, Baltimore, MD, USA

•  Recent Advances in Photo-Initiated Electron-Transfer at the Interface between Anatase TiO

2

Nanocrystallites and Transition-Metal Polypyridyl Compounds

Rufino M. Navarro

Institute of Catalysis and Petrochemistry, CSIC, Cantoblanco, Madrid, Spain

•  H

2

Production from Renewables

Sascha Ott

Uppsala University, Uppsala, Sweden

•  Toward Solar Fuels Using a Biomimetic Approach: Progress in the Swedish Consortium for Artificial Photosynthesis

Kenichi Oyaizu

Waseda University, Tokyo, Japan

•  Molecular Catalysis for Fuel Cells

Roy A. Periana

The Scripps Research Institute, Jupiter, FL, USA

•  Methane-to-Methanol Conversion

Helena Aguilar Ribeiro

Universidade do Porto, Porto, Portugal

•  Dye-Sensitized Solar Cells: an Overview

Sophie Romain

Institute of Chemical Research of Catalonia (ICIQ), Barcelona, Spain

•  Molecular Catalysts for Oxygen Production from Water

M. Cruz Sanchez-Sanchez

Institute of Catalysis and Petrochemistry, CSIC, Cantoblanco, Madrid, Spain

•  H

2

Production from Renewables

Asel Sartbaeva

University of Oxford, Oxford, UK

•  Hydrogen Economy

Stephen Skinner

Imperial College London, London, UK

•  Intermediate-Temperature Solid Oxide Fuel Cells

Stenbjörn Styring

Uppsala University, Uppsala, Sweden

•  Toward Solar Fuels Using a Biomimetic Approach: Progress in the Swedish Consortium for Artificial Photosynthesis

Ali T-Raissi

University of Central Florida, Orlando, FL, USA

•  Thermochemical Water-Splitting

Xiaoning Tian

National University of Singapore, Singapore

•  Supercapacitors: Electrode Materials Aspects

Gözde Ulas

Yale University, New Haven, CT, USA

•  Energy Conversion in Photosynthesis

Stephen A. Wells

University of Warwick, Coventry, UK

•  Hydrogen Economy

Li Yang

University of Rhode Island, Kingston, RI, USA

•  Thermal Stability of Lithium Ion Battery Electrolytes

Jintao Zhang

National University of Singapore, Singapore

•  Supercapacitors: Electrode Materials Aspects

Li Li Zhang

National University of Singapore, Singapore

•  Supercapacitors: Electrode Materials Aspects

Xiu Song Zhao

National University of Singapore, Singapore

•  Supercapacitors: Electrode Materials Aspects

Series Preface

The success of the Encyclopedia of Inorganic Chemistry (EIC) has been very gratifying to the editors. We felt, however, that not everyone would necessarily need access to the full ten volumes of EIC. Some readers might prefer to have more concise thematic volumes targeted to their specific area of interest. This idea encouraged us to produce a series of EIC Books, focusing on topics of current interest. These will continue to appear on a regular basis and will feature the leading scholars in their fields. Like the Encyclopedia, we hope that EIC Books will give both the starting research student and the confirmed research worker a critical distillation of the leading concepts and provide a structured entry into the fields covered.

Computer literature searches have become so easy that one could be led into thinking that the problem of efficient access to chemical knowledge is now solved. In fact, these searches often produce such a vast mass of material that the reader is overwhelmed. As Henry Kissinger has remarked, the end result is often a shrinking of one's perspective. From studying the volumes that comprise the EIC Books series, we hope that readers will find an expanding perspective to furnish ideas for research, and a solid, up-to-date digest of current knowledge to provide a basis for instructors and lecturers.

I take this opportunity of thanking Bruce King, who pioneered the Encyclopedia of Inorganic Chemistry, my fellow editors, as well as the Wiley personnel, and, most particularly, the authors of the articles for the tremendous effort required to produce such a series on time. I hope that EIC Books will allow readers to benefit in a more timely way from the insight of the authors and thus contribute to the advance of the field as a whole.

Robert H. CrabtreeYale University, New Haven, CT, USA

January 2009

Volume Preface

Energy production and storage are central problems for our time and are likely to attract intense public attention during many future decades. One factor will be the gradual decline in world petroleum production, as we pass the moment of peak production at some point in the next few years. The petroleum age is not over, of course, but the era of cheap petroleum does seem to be over. Oil wealth can also be associated with political instability, with unpredictable results on supply. A new factor—the economic rise of Asia and her vast population—can only aggravate the situation. Coal, the fossil fuel with the greatest reserves and with the broadest geographical distribution, may be able to fill any future energy supply gap but only at the cost of environmental damage at the mine and more intense CO2 emissions—coal having the highest CO2 output per unit of energy produced. Carbon capture and storage is under intense study but its practicality as a low-carbon-footprint means of using coal is still under discussion. Natural gas has been widely acclaimed as the best of the fossil fuels, having the lowest CO2 output per unit of energy produced. Hopes exist that abundant and widely distributed shale gas, previously considered uneconomic, may become viable with rising energy prices and new production methods.

A key factor that has intensified the growing unease over our current energy production system is the threat of climate change. David King, the UK Government's Chief Science Advisor from 2000 to 2007, has even called climate change “the single biggest challenge our civilization has ever had to face.” Nuclear energy is a potential solution but the problem of waste management has not yet been satisfactorily solved.

This volume is particularly concerned with alternative energy production and storage. Abundant energy is, in principle, available from the sun to run the earth in a sustainable way. Solar energy can be directly harnessed by agricultural and photovoltaic means but the sheer scale of the energy demand poses severe challenges. For example, any major competition between biomass production and food production would simply transfer scarcity from energy to food. Indirect use of solar energy in the form of wind is also promising, especially for those regions not blessed with abundant sunlight. Other modes such as tidal and wave energy may well be niche players.

These are problems in which chemistry can play a decisive role. The present volume covers some promising modes of alternative energy production and storage that minimize the atmospheric burden of fossil-derived CO2. No one production or storage mode is likely to dominate, at least at first, and numerous possibilities need to be explored to compare their technical feasibility and economics. This provides the context for a broad exploration of novel ideas that we are likely to see in future years as the field expands.

Water splitting is a central problem in alternative energy work. Only water is a sufficiently cheap and abundant electron source for global exploitation, as Jules Verne foresaw in his 1874 novel, The Mysterious Island, “water will be the coal of the future.” Of course, both energy input and suitable catalysts are needed to split water into oxygen and either hydrogen or electrons and protons. In this context, Brudvig and coauthors discuss energy conversion in photosynthesis, Llobet and coauthors cover molecular water splitting catalysts, Brewer and coauthors consider photocatalytic hydrogen production from water and T-Raissi covers thermochemical water splitting. Johannson and coauthors discuss recent progress in the Swedish Consortium for Artificial Photosynthesis. Batista discusses the progress made in computational modeling of energy-related processes including photosynthesis.

Several articles concentrate on hydrogen, notably a key contribution on the hydrogen economy by Edwards and coauthors and on hydrogen production from renewables by Fierro and coauthors.

A number of important chemical conversions are covered, for example reduction of CO2 to useful fuels either electrochemically or photochemically, as well as conversion of methane to methanol by Periana and coauthors.

Dye-sensitized solar cells for the direct conversion of solar to electrical energy is reviewed by Mendes and coauthors. Related to this problem, Meyer and coauthors discuss photoinitiated electron transfer in such cells.

A number of articles relate to fuel cells. Devanathan discusses the key problem of devising efficient proton exchange membranes, Brett covers intermediate temperature solid oxide fuel cells, Lee considers direct ethanol fuel cells, Oyaizu considers molecular catalysis for fuel cells, and Barrière covers the use of enzymes and microbes in fuel cells.

Batteries are also considered. Lucht and coauthors discuss Li ion batteries, Grey and coauthors cover L-6 MAS NMR studies on battery materials, and Zhao reviews the area of supercapacitors with special reference to the electrode materials.

It is likely that many more research groups will be moving into the area, attracted not only by the rising funding levels that we are already seeing but also by its major challenges as well as its interdisciplinarity.

Our field will greatly benefit from the current realignment of research priorities and this book provides an entry point for students and scholars considering a career in the field or needing an up-to-date review.

Robert H. CrabtreeYale University, New Haven, CT, USA

October 2010

Inorganic ChemicalStrategies for aWarming World

PART 1

Energy Production

H2 Production from Renewables

Rufino M. Navarro, M. Cruz Sanchez-Sanchez, M. Consuelo Alvarez-Galvan and Jose Luis G. Fierro

Institute of Catalysis and Petrochemistry, CSIC, Cantoblanco, Madrid, Spain

and

Saeed M. Al-Zaharani

King Saud University, Riyadh, Saudi Arabia

1 INTRODUCTION

Energy and environmental concerns are among the biggest challenges that the world is facing today, in particular, energy sustainability and carbon emission from the fossil fuels. Hydrogen is considered as one of the few long-term sustainable clean energy carriers, emitting only water vapor as a by-product during its oxidation or combustion. Although hydrogen can be used as a fuel in internal combustion engines (ICEs), the conversion of the chemical energy stored in the H–H bond into electricity in fuel cells is more attractive because of its higher efficiency.1

Production of H2 by the currently available technologies consumes greater amounts of natural gas, which in turn emits more greenhouse gas (GHG). However, in spite of using nonrenewable fossil fuel feedstock, the increase in GHG emissions can be reduced through CO2 sequestration at the production sites. Production of H2 from renewable sources derived from agricultural or other waste streams offers the possibility to contribute to the production capacity with lower or no net GHG emissions, without carbon sequestration technologies, increasing the flexibility and improving the economics of distributed and semicentralized reforming.

At present, steam reforming of hydrocarbons, i.e., natural gas, is the most commonly used and generally the most economical method for hydrogen production.2–5 The use of natural gas, whose major component is methane, fails to provide a solution to deal with the large amount of carbon dioxide emissions (ca 7 kg CO2/kg H2) during the reforming processes. In addition, the use of fossil fuels for secondary energy production is nonsustainable. Not only does fossil fuel burning contribute to the GHG pool but the eventual depletion of the world’s fossil fuel reserves also threatens sustainable development.6,7 However, hydrogen production can be environmentally friendly only if the resource used to extract hydrogen is renewable. Thus, biomass, a product of photosynthesis, is an attractive alternative to fossil feedstocks as it can be considered as a renewable H2 precursor. CO2-neutral hydrogen can be produced by the conversion of biomass via gasification,8 pyrolysis of bio-oils,9 steam reforming of biomass-derived higher alkanes and alcohols,2,5,10 and aqueous phase reforming (APR) of oxygenated hydrocarbons.11 Biomass-derived hydrogen can be classified as carbon neutral because the CO2 released during hydrogen production is further consumed by biomass generation (neglecting the CO2 produced from the fossil fuel energy required for operating the hydrogen production unit).12

(1)

Solar energy can be used to produce hydrogen in the form of heat (thermochemical), light (photoelectrochemical or photocatalytic), or electricity (electrolysis). Among these, thermochemical, photoelectrochemical, and photocatalytic are the most efficient solar paths to hydrogen since they do not have the inefficiencies associated with the conversion of solar energy to electricity followed by electrolysis.

In this article, we review the recent developments in the conversion involved in hydrogen production from less costly and abundant biomass without net carbon emissions. In addition, this article includes advances in the fully renewable conversion of solar energy into hydrogen via the water-splitting process assisted by thermochemical, photolectrochemical, and photocatalytic processes. Attention is particularly given to the new materials and strategies reported in the literature over the past years for developing efficient metal oxide redox cycles for a two-step thermochemical water splitting, efficient photoelectrocatalysts under visible light photocatalysts for hydrogen evolution via photoelectrochemical water splitting, and efficient photocatalysts under visible light for the photochemical water splitting.