Preparation of 2D square-like Bi2S3-BiOCl heterostructures with enhanced visible light-driven photocatalytic performance for dye pollutant degradation

A series of Bi2S3-BiOCl composites with two-dimensional (2D) square-like structures were prepared via a two-step anion exchange route. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and diffuse reflectance spectra (DRS) were used to investigate the properties of the as-prepared Bi2S3-BiOCl heterostructures. The coupling of BiOCl and Bi2S3 induced enhanced photoabsorption efficiency and bandgap narrowing. A reactive brilliant red X-3B dye was used as a contaminant to test the photocatalytic activity of the obtained Bi2S3-BiOCl samples under visible light irradiation. The sample Bi2S3-BiOCl with a mass ratio of 8:4 exhibited the highest photodegradation efficiency, which was six times higher than that of pure BiOCl. In addition, a mechanism for the enhancement of photocatalytic activity is proposed.