Efficient photocatalytic degradation of ciprofloxacin and bisphenol A under visible light using Gd2WO6 loaded ZnO/bentonite nanocomposite

The Gd2WO6/ZnO/bentonite (GWZB) nanocomposite was prepared by hydrothermal process and characterized. DRS spectra showed increased visible absorption with the band gap decrease of GWZ by the addition of bentonite. PL spectra of GWZ and GWZB revealed that intensity of GWZB photocatalyst is less than the GWZ photocatalyst due to decrease in electron-hole recombination, leading to the increase in photocatalytic activity of GWZB. From FE-SEM images, it is inferred that the entire catalyst surface has clustered microsponge-like structure with the number of cavities in surface area. GWZB was further characterized by FT-IR, EDX and XPS analysis. The photocatalytic activity was studied in the degradation of ciprofloxacin (CF) and bisphenol-A (BPA) in aqueous medium using visible light. Under irradiation for 60 min, the photodegradation of CF and BPA with 20 mg of GWZB are 97.9 and 98.3% respectively. Photodegradation was optimized by various forms of catalysts, catalyst dosage, the CF and BPA concentrations. GWZB is stable with good recycling performance for photodegrdation.