2D/1D Zn_0.7Cd_0.3S p-n heterogeneous junction enhanced with NiWO₄ for efficient photocatalytic hydrogen evolution

Bimetallic solid solutions have attracted much attention in the field of photocatalysis due to their excellent photocatalytic properties. Here, Zn_0.7Cd_0.3S solid solution with two morphologies was prepared by typical solvent-thermal method. The co-existence of 1D rod-like Zn_0.7Cd_0.3S and 2D sheet-like Zn_0.7Cd_0.3S can be found in SEM and TEM diagrams. This special structure can provide a larger specific surface area for exposing more active sites and expanding optical contact surface, which is favorable for boosting photocatalytic water-splitting reaction. In addition, a p-n junction formed by the interface contact between NiWO₄ and Zn_0.7Cd_0.3S effectively promotes the transfer of interfacial charges through the built-in electric field, and thus recombination of the electron-hole pairs is greatly inhibited. The highest photocatalytic H₂ production rate in the Na₂S/Na₂SO₃ system is 15.95 mmol h^-1 g^-1, which is 3.16 times higher than the bare Zn_0.7Cd_0.3S. Meanwhile, Mott-Schottky curves further confirmed the Zn_0.7Cd_0.3S and NiWO₄ suitable conduction band and valence band position, forming a more effective thermodynamic charge transfer path. This work provides for the first time 2D/1D structure of Zn_0.7Cd_0.3S and highlights the more efficient photocatalytic hydrogen evolution performance of the p-n junction in Zn_0.7Cd_0.3S/NiWO₄.