Cobalt and Carbon Co-doped Carbon Nitride for Enhanced Photocatalytic Hydrogen Evolution

The photocatalytic activity of carbon nitride is greatly limited by the low visible-light utilization and fast photocarries recombination. Here, a new cobalt and carbon co-doped carbon nitride (CNCoC) was prepared via a one -step thermal condensation method using vitamin B12 (VB12) as the cobalt and carbon source mixed with urea. The characterization results indicate that the cobalt and carbon co - doping does not change the morphology, skeleton structure or functional groups of carbon nitride. However, the co-doping contributes to the enhanced surface area, optimized band structure and increased visible-light absorption. More importantly, compared to carbon doping, the synergistic effect of cobalt and carbon co-doping leads to more efficient photocarrier separation and transport. As a result, the photocatalytic hydrogen evolution rate of CNCoC - 6 prepared with 6 mg VB12 reached 56.1 mu mol.h(-1 )under visible light irradiation, which was 3.05 times that of pure carbon nitride (CN). While the carbon doped carbon nitride (CNC-6) only exhibited a hydrogen evolution rate to be 2.55 times that of CN.