Anion-exchange synthesis of hollow BiOCl/Bi2S3 hybrids with superior capability for photocatalytic reduction of hexavalent chromium under visible light irradiation

BiOCl/Bi 2 S 3 hollow hybrids were synthesised through a mild anion-exchange method from BiOCl microspheres and thiacetamide. X-ray diffraction, scanning electron microscopy, transmission electron microscopy, nitrogen adsorption measurements, ultraviolet–visible–near-infrared diffuse reflectance spectra, photocurrent, and electrochemical impedance spectroscopy (EIS) were employed to study the composition, structure, and properties of the as-synthesised BiOCl/Bi 2 S 3 hybrids. Compared to pure Bi 2 S 3 and BiOCl products, the as-prepared BiOCl/Bi 2 S 3 hollow hybrids exhibited superior capability for photocatalytic reduction of hexavalent chromium under vis light irradiation. The photocurrent and EIS results demonstrated that the low recombination rate of photoinduced electron–hole pairs was contributed to the enhanced photoreduction activity.