A strategy to construct a highly active CoxP/SrTiO3(Al) catalyst to boost the photocatalytic overall water splitting reactions

Hydrogen production from overall water splitting using SrTiO3(Al)-based semiconductors is one of the most promising routes to address energy and environmental concerns. Noble metals are needed to accelerate water splitting by promoting the charge transfer and providing active sites. However, noble metal-based catalysts have high prices and rare resources. Herein, we demonstrate a strategy to construct highly active CoxP/SrTiO3(Al) for overall water splitting. Hydrothermal method followed by an ultrasonic process was applied to prepare CoxP dots, which were loaded on the whole surface of SrTiO3(Al) as bifunctional cocatalysts. Interestingly, the CoxP dots on the (110) planes of SrTiO3(Al) were partially oxidized for the OER reaction. However, CoxP dots on the (100) planes of SrTiO3(Al) for HER kept it as it was. The as-prepared CoxP/SrTiO3(Al) photocatalyst shows a stable HER rate of 1.36 mmol−1 h−1 and OER rate of 0.635 mmol−1 h−1. The strong interaction between CoxP and SrTiO3(Al) not only facilitates rapid charge separation but also provides a highly active site for overall water splitting. Our study provides a valuable method for constructing noble-metal-free SrTiO3(Al)-based photocatalysts.