Improved charge transfer by binary Ni3S2-NiS2 for boosting the photocatalytic hydrogen generation over g-C3N4

• A facile one-pot hydrothermal method to synthesize Ni 3 S 2 -NiS 2 /g-C 3 N 4 (CN). • Photocatalytic HER performance was enhanced with Ni 3 S 2 -NiS 2 as cocatalyst. • Ni 3 S 2 -NiS 2 /CN improves the light utilization and accelerates electron transfer. • Ni 3 S 2 -NiS 2 /CN facilitates the separation of photogenerated electron-hole pairs. Developing efficient, cheap and robust photocatalysts for hydrogen evolution is promising to solve the issues of energy shortage and environmental degradation. In this work, binary Ni 3 S 2 -NiS 2 was in-situ grown on g-C 3 N 4 (CN) through a one-pot hydrothermal method. The optimal hydrogen evolution activity (1206.6 μmol g -1 h −1 ) was achieved from Ni 3 S 2 -NiS 2 /CN-3 with excellent stability under visible light irradiation. Improved light absorption and superior interfacial charge transfer properties including suppressed photogenerated carrier recombination and efficient separation of photogenerated electron-hole pairs have been observed, which account for the enhanced photocatalytic performance.