Cr/S/TiO2-LOADED HOLLOW GLASS MICROSPHERES AS AN EFFICIENT AND RECYCLABLE CATALYST FOR THE PHOTOCATALYTIC DEGRADATION OF INDIGO CARMINE UNDER VISIBLE LIGHT

Chromium and sulfur co-doped nanometer TiO2 hollow glass microspheres (Cr/S/TiO2-HGM) were synthesized by a sol-gel method. Characterization used X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), N2 adsorption-desorption (Brunauer-Emmett-Teller (BET) measurements) and UV-Vis diffuse reflectance spectroscopy. The photocatalytic activity was evaluated by photodegradation of indigo carmine in an aqueous solution under visible light irradiation. The results indicated that the Cr/S/TiO2 containing 0.60% (atomic ratio) chromium and 1.2% (atomic ratio) sulfur calcined at 500 ºC for 2 h had high catalytic efficiency under visible light irradiation. The floating Cr/S/TiO2-HGM catalyst had greater photocatalytic activity than Cr/S/TiO2 powder. Therefore, Cr/S/TiO2-HGM is a promising, high-performing, visible-light-driven, and more reusable photocatalyst.