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

Photocatalytic H2 production via water splitting in a noble-metal-free photocatalytic system has attracted much attention in recent years. In this study, noble-metal-free Ni3N was used as an active cocatalyst to enhance the activity of g-C3N4 for photocatalytic H2 production under visible-light irradiation (λ > 420 nm). The characterization results indicated that Ni3N nanoparticles were successfully loaded onto the g-C3N4, which accelerated the separation and transfer of photogenerated electrons and resulted in enhanced photocatalytic H2 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-C3N4, and the apparent quantum yield (AQY) was ∼0.45% at λ = 420. Furthermore, the Ni3N/g-C3N4 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 Ni3N/g-C3N4 system is proposed.