Facile Construction of Cu<sub>3</sub>P/ZnIn<sub>2</sub>S<sub>4</sub> Heterojunctions for Efficient Photocatalytic Hydrogen Evolution
Ruolin Chen, Hongmiao Zhou, Changcun Han, Pan Wang, Ruoyu Wang, Zhifeng Liu, Xinguo Ma, Yizhong Huang
Abstract
The ZnIn2S4 (ZIS) powder that was synthesized by the hydrothermal method has excellent photocatalytic H2 evolution activity. Cu3P (CP) is a p-type semiconductor, often associated with an n-type catalyst to form a p–n junction by balancing the diffusion of the carrier with the electrical migration. Therefore, it is well suited as a photocatalytic cocatalyst. To further improve the hydrogen production activity of the semiconductor photocatalyst, the Cu3P/ZnIn2S4 (CP/ZIS) samples are obtained through simple mechanical mixing. X-ray photoelectron spectroscopy, X-ray diffraction, surface photovoltage, ultraviolet–visible diffuse reflection light, scanning electron microscopy, and transmission electron microscopy techniques were used to investigate the crystal morphologies, properties, and optical properties of a CP/ZIS photocatalyst. The optical properties, microstructures, and composition of surface elements of the composite have been fully characterized. Experiments found that the mixed sample absorbed a wider light range and had a better hydrogen production rate compared to the pure ZnIn2S4. When the doping content of the supported Cu3P cocatalyst is 0.5%, the optimal hydrogen production rate of the sample CP/ZIS is 5466 μmol·g–1·h–1, which is 1.7 times that of pure ZnIn2S4. A heterojunction was formed between ZnIn2S4 and Cu3P to favor the migration and separation of carriers, and thus photocatalytic activity on CP/ZIS, facilitating the rate of photocatalytic H2 production.