Photoelectrochemical solar water splitting: From basic principles to advanced devices (original) (raw)
Related papers
Recent progress in material selection and device designs for photoelectrochemical water-splitting
Renewable & Sustainable Energy Reviews, 2021
The development of renewable and sustainable energy sources along with efficient storing strategies has been the focus of utmost importance within the community to address the current energy crisis and rising energy demands. In this respect, solar hydrogen production through the route of photoelectrochemical (PEC) watersplitting is considered as a highly promising option. This review begins with a focus on understanding the PEC fundamentals in terms of the charge-transfer processes and energy requirements followed by the prerequisite properties of photoelectrode materials. We then highlighted the recent progress in different semiconductor materials and PEC device configurations. Various photoelectrode materials and device designs were classified based on their performances, with the realization of their advantages and limitations. Recent investigations in theoretical studies carried out in this field were summarised to understand the knowledge-gap and futuristic requirements. Challenges responsible for the limited efficiencies of the existing PEC water-splitting technology, considering both the material development and PEC device designs, have been discussed. Accordingly, certain possible strategies and solutions were recommended with an aim to make the PEC water-splitting a practically feasible technology.
Oriental Journal of Chemistry, 2016
To meet the future energy demand, Hydrogen has been accepted as a fuel for future. Out of several renewable methods to produce hydrogen, solar assisted splitting of water (Photoelectrochemical splitting of water) is emerging as a most desired method to produce hydrogen which is a advancement of Photovoltaic process. However, the efficiency of PEC cell is a matter of concern. Various strategies have been adopted by different researchers to increase the efficiency of the system especially using nanotechnology as a tool. In this article, attempts have been made to summarise different approaches applied to obtain effective and viable photoelectrochemical system for splitting water to obtain hydrogen an energy carrier.
Nanomaterials for photoelectrochemical water splitting – review
International Journal of Hydrogen Energy, 2018
Photoelectrochemical (PEC) water splitting using nanomaterials is one of the promising techniques to generate hydrogen in an easier, cheaper and sustainable way. By modifying a photocatalyst with a suitable band width material can improve the overall solar-tohydrogen (STH) energy conversion efficiency. Nanomaterials can tune their band width by controlling its size and morphology. In many studies, the importance of nanostructured materials, their morphological and crystalline effects in water splitting is highlighted. Charge separation and transportation is the major concern in PEC water splitting. Nanomaterials are having high surface to volume ratio which facilitates charge separation and suppress electron-hole pair recombination. This review focuses on the recent developments in water splitting techniques using PEC based nanomaterials as well as different strategies to improve hydrogen evolution.
Photoelectrochemical water splitting: An ideal technique for pure hydrogen production
2020
Department of Chemical Engineering, MBM Engineering College, Jai Narain Vyas University, Jodhpur-342 011,<br> Rajasthan, India<br> E-mail: nitu84.jalore@gmail.com, dr.sushilsaraswat@gmail.com<br> Manuscript received online 20 March 2020, accepted 12 June 2020 Photoelectrochemical (PEC) water splitting is one of the promising process to generate hydrogen in an easier and sustainable<br> way. Hydrogen production through PEC provides a green and sustainable source of energy and addresses the solar intermittency<br> problem. While considerable efforts have been made over the past several decades but till date, there is no solar<br> water splitting materials that simultaneously fulfills the high efficiency, long-term stability and low cost. In PEC, the semiconductor<br> materials must exhibit sufficient voltage on irradiation to split water, long-term stability against corrosion in the aqueous<br> electrolyte and the band edge potentials at...
Strategies for Semiconductor/Electrocatalyst Coupling toward Solar‐Driven Water Splitting
Advanced Science
with the consumption of fossil fuels. [1,2] Hydrogen (H 2) and fuel cell technologies have shown significant potential to empower this transition, able to substantially reduce carbon dioxide (CO 2) emissions and create a huge new market, as predicted recently by the Hydrogen Council. [3] Although H 2 is a clean energy carrier and shows flexibility of linking different energy sectors and energy transmission and distribution networks, the production of H 2 is currently not that "clean"-nearly 96% of global H 2 production is from thermochemical processes, [4] which not only deplete fossil fuels but also emit a large amount of CO 2. To decarbonize H 2 production, fossil-free processes such as electrochemical water splitting using "green" electricity or direct photoelectrochemical (PEC) water splitting must be widely deployed. PEC water splitting takes advantage of semiconductors as both the light absorber and energy converter, to store solar energy in the form of H 2 fuel. To make full use of the photogenerated electron-hole pairs, effective separation of electrons from holes and rapid charge transfer from the space charge region to the semiconductor/liquid junction that enables the chemical reaction are very important. For most semiconductors, even if their conduction/valence band edge is properly positioned with respect to the proton reduction potential or the water oxidation potential, the hydrogen evolution reaction (HER) or the oxygen evolution reaction (OER) kinetics on the bare semiconductor surfaces is usually so sluggish that Hydrogen (H 2) has a significant potential to enable the global energy transition from the current fossil-dominant system to a clean, sustainable, and low-carbon energy system. While presently global H 2 production is predominated by fossil-fuel feedstocks, for future widespread utilization it is of paramount importance to produce H 2 in a decarbonized manner. To this end, photoelectrochemical (PEC) water splitting has been proposed to be a highly desirable approach with minimal negative impact on the environment. Both semiconductor light-absorbers and hydrogen/oxygen evolution reaction (HER/OER) catalysts are essential components of an efficient PEC cell. It is well documented that loading electrocatalysts on semiconductor photoelectrodes plays significant roles in accelerating the HER/OER kinetics, suppressing surface recombination, reducing overpotentials needed to accomplish HER/OER, and extending the operational lifetime of semiconductors. Herein, how electrocatalyst coupling influences the PEC performance of semiconductor photoelectrodes is outlined. The focus is then placed on the major strategies developed so far for semiconductor/ electrocatalyst coupling, including a variety of dry processes and wet chemical approaches. This Review provides a comprehensive account of advanced methodologies adopted for semiconductor/electrocatalyst coupling and can serve as a guideline for the design of efficient and stable semiconductor photoelectrodes for use in water splitting.
Photoelectrochemical water splitting: current state of research and environmental impact assessment
Hydrogen is an energy carrier with great potential for usage, for example in as a fuel cell in vehicles. Hydrogen produces no pollutants when burnt, therefore if a renewable way of producing hydrogen could be realised it could prove to be a solution against global warming. Photoelectrochemical (PEC) water splitting is a way of obtaining renewable hydrogen, however this technology still faces a great deal optimisation issues. Solar to hydrogen efficiency as well as life time of the PEC devices are some of the issues that must be solved before PEC hydrogen can become market competitive. This thesis presents an overview of the research being carried out by scientists across the world, as well as provide a comparison of the different reactor types that are being researched. A life cycle assessment is also analysed, the analysis shows that if optimisation of PEC reactors are reached, PEC hydrogen could indeed become market competitive. The literature research also showed that a significant amount of the global energy demand could be covered by PEC hydrogen.
Net primary energy balance of a solar-driven photoelectrochemical water-splitting device
Energy & Environmental Science, 2013
A fundamental requirement for a renewable energy generation technology is that it should produce more energy during its lifetime than is required to manufacture it. In this study we evaluate the primary energy requirements of a prospective renewable energy technology, solar-driven photoelectrochemical (PEC) production of hydrogen from water. Using a life cycle assessment (LCA) methodology, we evaluate the primary energy requirements for upstream raw material preparation and fabrication under a range of assumptions of processes and materials. As the technology is at a very early stage of research and development, the analysis has considerable uncertainties. We consider and analyze three cases that we believe span a relevant range of primary energy requirements: 1550 MJ m À2 (lower case), 2110 MJ m À2 (medium case), and 3440 MJ m À2 (higher case). We then use the medium case primary energy requirement to estimate the net primary energy balance (energy produced minus energy requirement) of the PEC device, which depends on device performance, e.g. longevity and solar-to-hydrogen (STH) efficiency. We consider STH efficiency ranging from 3% to 10% and longevity ranging from 5 to 30 years to assist in setting targets for research, development and future commercialization. For example, if STH efficiency is 3%, the longevity must be at least 8 years to yield a positive net energy. A sensitivity analysis shows that the net energy varies significantly with different assumptions of STH efficiency, longevity and thermo-efficiency of fabrication. Material choices for photoelectrodes or catalysts do not have a large influence on primary energy requirements, though less abundant materials like platinum may be unsuitable for large scale-up.
Photoelectrochemical water splitting: an idea heading towards obsolescence?
Energy & Environmental Science, 2018
The production of hydrogen from water and sunlight is a way to address the intermittency in renewable energy production, while simultaneously generating a versatile fuel and a valuable chemical feedstock. All approaches to solar hydrogen are, however, no equally promising.
Chemistry: A European Journal, 2017
Photoelectrochemical (PEC) water splitting using a combination of a photocathode and photoanode is one of the most promising methods of producing hydrogen from water employing sunlight. Recent reports have shown that surface modification of the photoelectrodes dramatically improves their PEC performance. Bare photoelectrodes often exhibit insufficient depletion regions, undesired surface states and/or degradation due to photocorrosion. It has been demonstrated that surface modifications can tune the flat-band potentials, band-edge potentials, surface states and chemical stabilities of these electrodes and thus improve quantum efficiency, onset potential and durability. This review describes in detail the various surface modification materials that have been developed to date, and the functions of these modifiers. This information is expected to provide guidelines for the future development of photoelectrodes capable of highly efficient and stable PEC water splitting.