Co3C as a promising cocatalyst for superior photocatalytic H2 production based on swift electron transfer processes

Abstract

Photocatalytic hydrogen production using solar energy has been envisaged as an ultimate energy solution for the future. However, expensive and noble-metal based photocatalysts limit its industrial applications. Herein, highly efficient photocatalytic H₂ production has been achieved using Co₃C as a noble-metal-free cocatalyst on CdS nanorods (NRs). An enhanced hydrogen evolution rate of 315 μmol h⁻¹ was obtained using the optimized photocatalyst. 420 nm light, an apparent quantum yield of 19% was achieved which is among the best reported carbide-based catalysts. To study the versatile role of Co₃C as a cocatalyst, ZnIn₂S₄ and g-C₃N₄ nanosheets were employed as photosensitizers. The obtained results successfully demonstrated that Co₃C has the ability to play a role as a universal cocatalyst for photocatalytic H₂ production. Electrochemical and spectroscopic studies were utilized to propose an appropriate mechanism for the present excellent photocatalytic H₂ production. This study showed that Co₃C has excessive potential as a promising cocatalyst for inexpensive H₂ production.