Energy Conversion In Natural And Artificial Photosynthesis

This book discusses the basic principles and processes of solar energy conversion in natural photosynthesis. It then directly compares them with recent developments and concepts currently being pursued in artificial photosynthetic systems that are capable of utilizing sunlight to convert carbon dioxide and water into a chemical fuel. In this regard, the main focus is on photoelectrochemical cells, in which semiconducting photoanodes and -cathodes modified with (electro-) catalysts are used to oxidize water, produce hydrogen and reduce carbon dioxide in a monolithic device. The fundamental photochemical and photophysical processes involved are presented and discussed, along with protection mechanisms and efficiency calculations for both natural and artificial photosynthesis. In turn, key parameters that are crucial for the efficient operation of natural photosynthesis are identified. Lastly, their validity and applicability in the design of artificial solar-driven water-splitting systems are examined.

In the modern world, to meet increasing energy demands we need to develop new technologies allowing us to use eco-friendly carbon-neutral energy sources. Solar energy as the most promising renewable source could be the way to solve that problem, but it is variable depending on day time and season. From this side, the understanding of photosynthesis process could be of significant help for us to develop effective strategies of solar energy capturing, conversion, and storage. Plants, algae, and cyanobacteria perform photosynthesis, annually producing around 100 billion tons of dry biomass. Presently, the detailed studies of photosynthetic system structure make functional investigations of the photosynthetic process available, allowing scientists to construct artificial systems for solar energy transduction. This book summarizes exciting achievements in understanding of photosynthetic structures and mechanisms of this process made by world leaders in photosynthesis field, and contains information about modern ideas in development of revolutionary new technologies of energy conversion. Organized according to the natural sequence of events occurring during photosynthesis, the book includes information of both photosynthetic structures and mechanisms and its applications in bioenergetics issues.

This technical book explores current and future applications of solar power as an unlimited source of energy that earth receives every day. Photosynthetic organisms have learned to utilize this abundant source of energy by converting it into high-energy biochemical compounds. Inspired by the efficient conversion of solar energy into an electron flow, attempts have been made to construct artificial photosynthetic systems capable of establishing a charge separation state for generating electricity or driving chemical reactions. Another important aspect of photosynthesis is the CO2 fixation and the production of high energy compounds. Photosynthesis can produce biomass using solar energy while reducing the CO2 level in air. Biomass can be converted into biofuels such as biodiesel and bioethanol. Under certain conditions, photosynthetic organisms can also produce hydrogen gas which is one of the cleanest sources of energy.

This comprehensive book systematically covers the fundamentals in solar energy conversion to chemicals, either fuels or chemical products. It includes natural photosynthesis with emphasis on artificial processes for solar energy conversion and utilization. The chemical processes of solar energy conversion via homogeneous and/or heterogeneous photocatalysis has been described with the mechanistic insights. It also consists of reaction systems toward a variety of applications, such as water splitting for hydrogen or oxygen evolution, photocatalytic CO2 reduction to fuels, and light driven N2 fixation, etc. This unique book offers the readers a broad view of solar energy utilization based on chemical processes and their perspectives for future sustainability.

This book explains the conversion of solar energy to chemical energy and its storage. It covers the basic background; interface modeling at the reacting surface; energy conversion with chemical, electrochemical and photoelectrochemical approaches and energy conversion using applied photosynthesis. The important concepts for converting solar to chemical energy are based on an understanding of the reactions’ equilibrium and non-equilibrium conditions. Since the energy conversion is essentially the transfer of free energy, the process are explained in the context of thermodynamics.

"Since the first report on solar fuels production by Fujishima and Honda in 1972, photoelectrochemical/electrochemical production of fuels, such as H2, carbonhydrates, etc., has significantly advanced over the past few decades with the remarkable development in new catalytic materials, fundamental knowledge, and new applications. In particular, the efficiency for solar fuels production steadily increases, for example, solar H2 production efficiency has reached 1.1% in term of the solar-to-hydrogen energy conversion efficiency. These progresses render solar fuels as promising candidates for use in modern technology. In the book Artificial Photosynthesis: From Materials to Devices, experts in the photoelectrochemical/electrochemical field discuss new catalytic materials as well as their photophysical properties and applications for artificial photosynthesis. This book covers the topical research in artificial photosynthesis from conventional particulate catalysts and porous/2D materials to the cutting-edge use of these materials in device fabrication for photoelectrochemistry and electrochemistry, as well as theoretical studies. In terms of applications, this book centers on CO2 photoreduction to valuable carbohydrates and water dissociation into high energy density H2. Throughout the book, examples and illustrations of applications are chosen to help the readers comprehend the achievements and trends in this rapidly evolving field. This book also provides the state-of-the-art research techniques in artificial photosynthesis. This book is informative and helpful for researchers, graduates, and advanced undergraduates interested in the CO2 reduction and water splitting and will assist them to quickly appreciate the research progresses in this field"--

Jules Verne (1828-1905), author of Around the World in Eighty Days (1873) and Journey to the Center of the Earth (1864), wrote in 1875 “I believe that water will one day be used as a fuel, because the hydrogen and oxygen which constitute it, used separately or together, will furnish an inexhaustible source of heat and light. I therefore believe that, when coal (oil) deposits are oxidised, we will heat ourselves by means of water. Water is the fuel of the future” Solar energy is the only renewable energy source that has sufficient capacity for the global energy need; it is the only one that can address the issues of energy crisis and global climate change. A vast amount of solar energy is harvested and stored via photosynthesis in plants, algae, and cyanobacteria since over 3 billion years. Today, it is estimated that photosynthesis produces more than 100 billion tons of dry biomass annually, which would be equivalent to a hundred times the weight of the total human population on our planet at the present time, and equal to a global energy storage rate of about 100 TW. The solar power is the most abundant source of renewable energy, and oxygenic photosynthesis uses this energy to power the planet using the amazing reaction of water splitting. During water splitting, driven ultimately by sunlight, oxygen is released into the atmosphere, and this, along with food production by photosynthesis, supports life on our earth. The other product of water oxidation is “hydrogen” (proton and electron). This ‘hydrogen’ is not normally released into the atmosphere as hydrogen gas but combined with carbon dioxide to make high energy containing organic molecules. When we burn fuels we combine these organic molecules with oxygen. The design of new solar energy systems must adhere to the same principle as that of natural photosynthesis. For us to manipulate it to our benefit, it is imperative that we completely understand the basic processes of natural photosynthesis, and chemical conversion, such as light harvesting, excitation energy transfer, electron transfer, ion transport, and carbon fixation. Equally important, we must exploit application of this knowledge to the development of fully synthetic and/or hybrid devices. Understanding of photosynthetic reactions is not only a satisfying intellectual pursuit, but it is important for improving agricultural yields and for developing new solar technologies. Today, we have considerable knowledge of the working of photosynthesis and its photosystems, including the water oxidation reaction. Recent advances towards the understanding of the structure and the mechanism of the natural photosynthetic systems are being made at the molecular level. To mimic natural photosynthesis, inorganic chemists, organic chemists, electrochemists, material scientists, biochemists, biophysicists, and plant biologists must work together and only then significant progress in harnessing energy via “artificial photosynthesis” will be possible. This Research Topic provides recent advances of our understanding of photosynthesis, gives to our readers recent information on photosynthesis research, and summarizes the characteristics of the natural system from the standpoint of what we could learn from it to produce an efficient artificial system, i.e., from the natural to the artificial. This topic is intended to include exciting breakthroughs, possible limitations, and open questions in the frontiers in photosynthesis research.

“Photosynthesis: Plastid Biology, Energy Conversion and Carbon Assimilation” was conceived as a comprehensive treatment touching on most of the processes important for photosynthesis. Most of the chapters provide a broad coverage that, it is hoped, will be accessible to advanced undergraduates, graduate students, and researchers looking to broaden their knowledge of photosynthesis. For biologists, biochemists, and biophysicists, this volume will provide quick background understanding for the breadth of issues in photosynthesis that are important in research and instructional settings. This volume will be of interest to advanced undergraduates in plant biology, and plant biochemistry and to graduate students and instructors wanting a single reference volume on the latest understanding of the critical components of photosynthesis.