Ultrafast synthesis of near-zero-cost S-doped Ni(OH)2 on C3N5 under ambient conditions with enhanced photocatalytic activity

Planting highly efficient and low-cost Ni-based noble-metal-free active sites on semiconductors is of great significance in the field of photocatalysis. Herein, taking wide visible-light-responsive 2D C3N5 as a model semiconductor, an impressive near-zero-cost 2D S-doped nickel hydroxide (S–Ni(OH)2) is grown on C3N5 ultrafast within 30 min under ambient conditions by facile reaction between extremely low-cost Ni(NO3)2 and Na2S in aqueous solution. The fabricated 2D S–Ni(OH)2–C3N5 hybrid exhibits enhanced photocatalytic performance for both H2 production from water and NO removal for air purification. The H2 production rate on S–Ni(OH)2–C3N5 is ∼7 times higher than that of Ni(OH)2–C3N5 and even slightly higher than that of Pt–C3N5, demonstrating its potential as a candidate for noble metal catalysts like Pt. In particular, an apparent quantum yield (AQY) value of 30.9% at 420 nm for H2 production is reached on 1.0 wt% S–Ni(OH)2–C3N5 due to quick internal charge transfer efficiency. In addition, ∼42% of NO can be purified in a continuous flow reaction system. This work affords a cost-efficient strategy to steer the photocatalytic property of Ni-based catalysts.