Dual photoelectrodes in photoelectrochemical water splitting

Abstract

Photoelectrochemical (PEC) water splitting (WS) holds much promise as a route for the production of hydrogen from solar power. Artificial photosynthesis to store hydrogen produced from solar energy via WS is an attractive topic currently receiving much attention. In a photoelectrochemical cell, water is oxidized to oxygen in the photoanode, and water is reduced to hydrogen in the photocathode. This requires the development of the following: (1) stable electrocatalysts to accelerate processes at each electrode; (2) water-splitting-compatible photosensitizers that efficiently absorb visible light and generate a charge-separated state. In this chapter, we will have an in-depth study of dual electrodes and their different types of arrangement, including tandem and parallel cells. Then, in each case, we discuss PEC/PEC and PEC/PV cells regarding material selection and device optimization. Finally, we provide a brief explanation of PV/EL cells. In the end, we will talk about the perspective of the upcoming challenges, focusing on the critical issues of design and different device structures and their performance limitations from the aspects of photoanode and photocathode. © 2024 Elsevier Ltd. All rights reserved.