Synthesis and characterization of BiOCl‐CoWO ₄ nanocomposites with improved photocatalytic activity

Abstract We have synthesized novel BiOCl‐CoWO ₄ heterostructured nanocomposites through chemical precipitation route with different amount of CoWO ₄ using KCl as Cl source at a temperature of 100°C, 4 hours. X‐ray diffraction, transmission electron microscopy, UV‐visible NIR spectroscopy, photoluminescence spectroscopy, N ₂ adsorption‐desorption isotherms, and electrochemical impedance spectroscopy were performed to gain the crystal structure, morphology, optical properties, surface area, and charge separation of the prepared photocatalysts. BiOCl‐CoWO ₄ composites demonstrated the diffraction peaks of both monoclinic CoWO ₄ nanoparticles and tetragonal BiOCl indicating the formation of the nanocomposite. TEM observations have shown that CoWO ₄ nanoparticles were deposited on the BiOCl surface. Photoluminescence, fluorescence lifetime study, and Electrochemical impedance spectroscopy responses of materials indicated a good separation efficiency of charge carriers in BiOCl‐CoWO ₄ ‐1. The photodegradation efficiency of the prepared materials was assessed by the decomposition of rhodamine B (RhB) dye solution under sunlight irradiation. Among the synthesized materials, the BiOCl‐CoWO ₄ ‐1 composite photocatalyst exhibited maximum photocatalytic activity. Thus the resulting heterostructure favored the efficient charge and energy transfer between BiOCl and CoWO ₄ nanoparticles across the interface. The investigations from the radical scavenger tests showed that photogenerated h ⁺ , O ₂ ^{∙ −} , and ^• OH radicals were involved in the photodegradation of RhB.