An efficient and stable WO3/g-C3N4 photocatalyst for ciprofloxacin and orange G degradation

In this work, the WO3/g-C3N4 heterojunction system has been prepared through a sonochemical process at 37 kHz. The composites were characterized by powder X-ray diffraction, diffuse reflectance and Fourier transform infrared spectroscopies, scanning electron microscopy and nitrogen adsorption-desorption measurements. The photocatalytic activity of the coupled system was evaluated by the photodegradation of the Orange G dye and the ciprofloxacin antibiotic under solar-like irradiation conditions. In this regard, the sample with 5 wt.% WO3 exhibited the higher photoactive behavior than the single WO3 and g-C3N4 materials. The role of the photogenerated holes, hydrogen peroxide (H2O2), hydroxyl radicals and superoxide ions were examined by means of the radical scavengers RI, catalase, 2-propanol and benzoquinone, respectively. Furthermore, the reusability of the WO3/g-C3N4 system was tested through repetitive photodegradation tests where the photocatalyst exhibits a similar photoactive behavior after three cycles.