Design of photoelectrochemical cells for water splitting

Abstract

This chapter discusses the photoelectrochemical (PEC) systems for solar water splitting, highlighting their potential to convert solar energy into chemical fuels, specifically hydrogen, and oxygen. It also emphasizes the challenges of developing semiconductor (SC) materials with appropriate energy levels and band gaps for effective catalytic water splitting. Photosensitizers, electrolytes, anchoring groups, and photocatalysts have been shown to significantly influence the performance of dye-sensitized photoelectrochemical cells (DSPECs) as a cost-effective and sustainable approach for water splitting. This chapter introduces photocatalytic materials, particularly perovskite-based catalysts, known for their high photocatalytic activity. Moreover, it addresses the performance limitations in current solar water-splitting systems, noting that the sun-to-hydrogen (STH) efficiency is still significantly less than the 10% target efficiency for large-scale applications. The discussion includes optimizing the band gap of SC materials, mentioning that a band gap of 1.23 eV is critical for effective water splitting. Lastly, the chapter introduces innovative tandem configuration systems that combine photoanodes and photocathodes or photovoltaic devices to maximize solar energy capture and achieve self-driven water splitting without the need for significant external bias. © 2025 Elsevier Inc. All rights reserved.