Photocatalytic hydrogen production from seawater splitting: Current status, challenges, strategies and prospective applications

The utilization of photocatalysis technology for solar-driven water splitting is a highly promising approach to produce green hydrogen fuel. This renewable energy has significant promise for progressively replacing fossil fuels in the foreseeable future. In order to efficiently take advantage of endless natural energies and address the current scarcity of freshwater resources, the usage of saltwater sources has garnered significant interest and emerged as a promising solution in the water-splitting photocatalysis field for hydrogen generation. Nevertheless, the complex components in seawater that cause high photo-corrosions and the use restrictions on appropriate photocatalysts have resulted in a relatively low number of studies on hydrogen production from seawater splitting compared to those in pure water solutions. This review aims to provide a comprehensive understanding of the current advancements in photocatalytic seawater splitting. It focuses on various aspects, including seawater properties, thermodynamics- kinetics and fundamental mechanisms in photocatalytic seawater splitting, solar-driven conversion efficiency, state-of-the-art photocatalyst design, and the main factors affecting the photocatalytic seawater-splitting performance. Additionally, it summarizes the latest strategies for hydrogen production designed to solve the challenges and limitations associated with the overall seawater splitting reaction. This work provides an overview of the present status and future development of green fuels derived from photocatalytic seawater splitting.