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

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 CoP/SrTiO₃(Al) for overall water splitting. Hydrothermal method followed by an ultrasonic process was applied to prepare CoP dots, which were loaded on the whole surface of SrTiO₃(Al) as bifunctional cocatalysts. Interestingly, the CoP dots on the (110) planes of SrTiO₃(Al) were partially oxidized for the OER reaction. However, CoP dots on the (100) planes of SrTiO₃(Al) for HER kept it as it was. The as-prepared CoP/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 CoP 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.