Ag-TON nanospheres coupled with fly ash cenospheres for wastewater treatment under visible light irradiation.

Using tetra-n-butyl titanate as raw material and fly ash cenospheres (FAC) as carrier, the photocatalysts of Ag-TON/FAC were successfully prepared by solvothermal and in-situ hydrolysis method. These visible light photocatalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), fluorescence spectroscopy (FL) and UV-vis diffuse reflectance spectra (DRS). In this study, methyl orange and ciprofloxacin were used as wastewater degradation targets to investigate the effect of the amount of titanium dioxide and the amount of Ag doping on the activity of photocatalysts. On the basis of this, the optimal ratio of TiO to FAC was 2:1 and the optimum doping ratio of Ag was determined to be 15 wt.%. The composite photocatalysts dispersed uniformly and were easy to recycle and reuse, which were benefits in fully utilizing the solar energy. The degradation efficiency remained at more than 60% after being renewed five times for MO and ciprofloxacin. The photocatalysts of Ag-TON/FAC can reduce the environmental burden caused by FAC also.