Materials for Solar-Driven Water Splitting

Solar water splitting technology is a fast-rising approach and has offered a promise of producing renewable H2 at a lower cost using non-toxic, inexpensive, and scalable materials for several years. Techno-economic analysis demonstrates that renewable H2 production using direct solar water splitting can compete with photovoltaic (PV)-electrolyser technology if specific device stability and solar-to-hydrogen (STH) efficiency using scalable and earth-abundant semiconductor-based photoelectrodes are met. Various earth-abundant semiconductor materials as photoelectrodes have been designed and engineered to achieve enhanced water splitting performance. However, the poor STH efficiency and device stability of these earth-abundant photoelectrodes are the current challenges of solar water splitting technology to produce renewable H2 at a large scale. The chapter explores solar-driven hydrogen production, focusing on efficient light absorption, charge separation, and catalytic processes. Key materials for semiconductor photocatalysts, photoelectrodes, and cocatalysts are discussed, highlighting their design principles and properties for solar energy conversion. Recent advancements, such as nanostructuring and surface modifications, are explored for improved light harvesting and catalytic activity. The chapter addresses challenges, including the poor STH efficiency and device stability, and presents an outlook on emerging materials and technologies like perovskite-based materials and earth-abundant catalysts. It concludes by emphasizing the importance of interdisciplinary collaborations and continued research efforts to accelerate the development and deployment of materials for solar-driven hydrogen production, contributing to renewable energy innovation.