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

Abstract

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