Water splitting photocatalysts for solar hydrogen production on a large scale

This paper presents a mini review on overall water splitting using particulate photocatalysts. Two main approaches exist: the one-step method, which employs a single photocatalyst, and the two-step method (also referred to as the Z-scheme), which utilizes two different photocatalysts. In this review, we focus on the single-photocatalyst approach. Particular attention is given to the photocatalysts developed by our group, namely, ultraviolet-responsive Al-doped strontium titanate (SrTiO[Formula: see text], as well as visible-light-responsive systems such as the gallium nitride–zinc oxide solid solution (GaN:ZnO) and tantalum nitride (Ta 3 N[Formula: see text].