Particulate photocatalysts for overall water splitting

Hydrogen is an inexpensive, renewable, environmentally-friendly and carbon-neutral fuel, and so is one of the most promising alternatives to fossil fuels. Solar-driven overall water splitting (OWS) using particulate photocatalysts is a potentially ideal approach to realizing hydrogen evolution technology. At present, although a variety of potential photocatalyst materials have been developed, the limited solar-to-hydrogen energy conversion efficiency of existing systems continues to hinder the practical application of OWS technology. This article introduces the basic principles of photocatalytic water splitting and summarizes the progress and challenges related to the use of particulate photocatalysts in OWS applications. Various strategies and working mechanisms associated with the development of single photocatalyst and Z-scheme photocatalyst systems are discussed and the latest achievements in the practical implementation of scalable photocatalyst panel reactors are examined.