Construction and photocatalytic properties of WS₂/BiOCl heterojunction

Bismuth oxyhalide BiOX (X=Cl, Br, I) as a new photocatalyst, its series of BiOX, and composite photocatalyst materials have attracted much attention. In this paper, we used Bi(NO₃)₃⋅5H₂O, NaOH, and WS₂ as raw materials to prepare WS₂/BiOCl heterojunction composite materials by in situ construction method, and using X-ray diffraction, EDS element mapping, and other analytical means found the crystallization of WS₂/BiOCl composite materials. With the increase of the mass ratio of WS₂, the XRD peak of WS₂ in the composite became sharp gradually. The visible light response range of BiOCl increased, and the band gap became narrow. The recombination probability of photogenerated electron-hole pair decreased. BiOCl (1–2 μm) was stacked on the WS₂ (2–5 μm) layer, and formed the WS₂/BiOCl heterostructure. The results showed that 7%-WS₂/BiOCl had the best adsorption effect, and the degradation efficiency reached 95.83% at 240 min. At the same time, the active groups in the photocatalytic degradation process are ⋅OH and h⁺. Through the first-order kinetic simulation, the reaction rate constant of 7%-WS₂/BiOCl was 0.0155 min^− 1, which was 4.2 times that of BiOCl. After four cycles of experiments, it still had stable photocatalytic activity.