Co₃C as a promising cocatalyst for superior photocatalytic H₂production based on swift electron transfer processes

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 H₂production has been achieved using Co₃C as a noble-metal-free cocatalyst on CdS nanorods (NRs). An enhanced hydrogen evolution rate of 315 μmol h⁻¹was 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, ZnIn₂S₄and g-C₃N₄nanosheets were employed as photosensitizers. The obtained results successfully demonstrated that Co₃C has the ability to play a role as a universal cocatalyst for photocatalytic H₂production. Electrochemical and spectroscopic studies were utilized to propose an appropriate mechanism for the present excellent photocatalytic H₂production. This study showed that Co₃C has excessive potential as a promising cocatalyst for inexpensive H₂production.