Integrating non-precious-metal cocatalyst Ni3N with g-C3N4 for enhanced photocatalytic H2 production in water under visible-light irradiation

Photocatalytic H 2 production via water splitting in a noble-metal-free photocatalytic system has attracted much attention in recent years. In this study, noble-metal-free Ni 3 N was used as an active cocatalyst to enhance the activity of g-C 3 N 4 for photocatalytic H 2 production under visible-light irradiation ( λ > 420 nm). The characterization results indicated that Ni 3 N nanoparticles were successfully loaded onto the g-C 3 N 4 , which accelerated the separation and transfer of photogenerated electrons and resulted in enhanced photocatalytic H 2 evolution under visible-light irradiation. The hydrogen evolution rate reached ∼305.4 μmol h −1 g −1 , which is about three times higher than that of pristine g-C 3 N 4 , and the apparent quantum yield (AQY) was ∼0.45% at λ = 420. Furthermore, the Ni 3 N/g-C 3 N 4 photocatalyst showed no obvious decrease in the hydrogen production rate, even after five cycles under visible-light irradiation. Finally, a possible photocatalytic hydrogen evolution mechanism for the Ni 3 N/g-C 3 N 4 system is proposed.