Ni2P–Ni2P4O12 enhanced CdS nanowires for efficient visible light photocatalytic hydrogen production

Intrinsic charge carrier recombination, narrow visible light absorption and poor durability restrain the photoactivity for solar-to-H 2 production. Here, noble-metal-free binary co-catalyst Ni 2 P–Ni 2 P 4 O 12 was synthesized by a simple one-step thermal phosphorylation method for enhancing CdS nanowires in visible-light-driven hydrogen generation, where the CdS nanowires are uniformly dispersed on the surface of Ni 2 P–Ni 2 P 4 O 12 through in-situ solvothermal strategy. The photocatalytic hydrogen production rate of 5 ​wt% Ni 2 P–Ni 2 P 4 O 12 /CdS nanowires can reach 5093 ​μmol ​g −1  ​h −1 using Na 2 S–Na 2 SO 3 as sacrificial agent under the irradiation of visible light (λ ​> ​420 ​nm), which is about 16 times for CdS nanowires (316 ​μmol ​g −1  ​h −1 ). In the cycling experiments, the composite catalyst shows good stability and the hydrogen production rate remains about 83% of the initial value. The interface structure construction between CdS nanowires and Ni 2 P–Ni 2 P 4 O 12 result in the excellent photocatalytic activity , broaded visible light absorption and stability. Specifically, Ni 2 P–Ni 2 P 4 O 12 can effectively promote the separation of electron hole pairs in space, in which Ni 2 P 4 O 12 can accept H + ions and Ni 2 P can reduce the over potential of H + reduction, resulting in the synergically promotion in the photocatalytic activity. The cost-effective ternary photocatalyst exhibits great potential for sustainable and high-efficiency photocatalytic water splitting, and Ni 2 P–Ni 2 P 4 O 12 may be suitable to modify a wider variety of semiconductor photocatalysts.