Construction of Ag2WO4 decorated CoWO4 nano-heterojunction with recombination delay for enhanced visible light photocatalytic performance and its antibacterial applications

In the present work, CoWO4/Ag2WO4 nanocomposite (CWO/AWO NCs) was fabricated via sono-chemical method for the evaluation of photocatalytic and antimicrobial activity. The optical property, morphology and phase structures of CWO/AWO NCs were investigated by high-resolution transmission electron microscope (HR-TEM), X-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR), Photoluminescence (PL), Brunner-Emmett-Teller surface area analyzer (BET), UV-visible diffuse reflectance spectroscopy (UV-vis DRS), Electron impedance spectroscopy (EIS) and X-ray photoelectron spectroscopy (XPS). XRD and selected area electron diffraction (SAED) pattern confirmed that the particle was crystalline in nature. The optical property of CWO/AWO NCs showed that the particle possesses band gap energy of 2.66 eV, which enables the particle to degrade methylene blue (MB) under visible light. The results indicate that the photocatalytic degradation of MB by CWO/AWO NCs (94.4%) was higher than individual AWO (57.2%) and CWO (22.6%). The prepared photocatalyst showed excellent activity for the degradation of MB dye and the reaction follows first order kinetics. The OH center dot radical played major role in catalytic activity on the degradation of MB and it was confirmed by radical trapping experiment. The antimicrobial activity of CWO/AWO NCs was examined against B. subtilis and E. coli. The reusability of CWO/AWO NCs was studied by 6 cycles test and the reusable efficiency was 97.3%. The prepared NCs can be effective for the rapid removal of toxic organic pollutant present in the environmental water bodies.