A Ga Doped NiTiO3 Photocatalyst for Overall Water Splitting under Visible Light Illumination

Photocatalytic overall water splitting (OWS) is an appealing strategy to convert solar energy and produce hydrogen fuel. NiTiO3 (NTO) is an earth-abundant material, which is studied as a robust photocatalyst with broad absorptance of sunlight spectrum, ranging from ultraviolet to infrared regions. Herein, by a rational design of an NTO-based photocatalytic system, the activity for photocatalytic OWS is realized under both ultraviolet and visible light illuminations, and H2 and O2 evolution is achieved within the stoichiometric ratio of 2:1. Specifically, Gallium is doped into the NTO crystal to activate the material for photocatalytic OWS by improving photoexcited charge migration. Meanwhile, Co and Pt species are screened out as the oxygen evolution and hydrogen evolution co-catalysts, respectively. Theoretical stimulations, steady state experiments, and operando characterizations are acquired to investigate the OWS performance. This research paves the pathway to apply this small-bandgap photocatalyst for OWS by maximizing the solar energy harvesting.