Non-Precious Co0.85Se Cocatalyst Boosts Visible-Light-Driven Hydrogen Evolution on g-C3N4 by 53-Fold

The development of cost-effective, efficient, and visible-light-responsive photocatalysts for hydrogen evolution is pivotal for addressing global energy shortages and environmental degradation. In this context, non-precious metal cocatalysts have garnered significant attention for modifying semiconductor photocatalysts. Herein, a high-performance Co0.85Se/g-C3N4 composite photocatalyst was successfully synthesized via a facile solvothermal method, where transition metal Co0.85Se nanoparticles were grown on g-C3N4 nanosheets in situ. The optimized 6-Co0.85Se/g-C3N4 composite exhibited a superior photocatalytic hydrogen evolution rate of 426 µmol·g−1·h−1 under visible light irradiation, which is approximately 53 times higher than that of pristine g-C3N4. Experimental characterizations revealed that the Co0.85Se nanoparticles were well dispersed on the g-C3N4 nanosheets without obvious agglomeration, which significantly broadened the visible-light absorption range of the composite. Furthermore, photoelectrochemical measurements confirmed that the Co0.85Se cocatalyst effectively accelerated charge separation and migration kinetics. Consequently, the construction of this heterojunction endows the composite with excellent photocatalytic performance. This work offers new insights into the design of efficient, non-precious metal-based photocatalysts for sustainable hydrogen production.