Effective synthesis of nanoscale anatase TiO2 single crystals using activated carbon template to enhance the photodegradation of crystal violet

Nanoscale anatase TiO2 single crystals were successfully synthesized using three kinds of activated carbon (AC) templates through a simple sol-gel method. The optimal photocatalyst (T-WOAC) was obtained using wood-based AC template. X-ray diffraction, transmission electron microscopy and Brunauer-Emmett-Teller analyses revealed that T-WOAC possessed a small crystallite size of 8.7 nm and a clear mesoporous structure. The photocatalytic properties of samples were then evaluated through photodegradation of crystal violet (CV). Results implied that the photocatalysts prepared using the AC templates exhibited superior photocatalytic activity to that of the original TiO2. This enhancement may be due to the small crystallite size, large specific surface area and pore volume of the catalysts prepared with ACs. T-WOAC showed high photocatalytic activity, CV degradation of 99.01% after 120 min of irradiation and k = 0.03914 min(-1), which is 3.9 times higher than that of the original TiO2 (k = 0.00994 min(-1)). This result can be mainly attributed to the application of WOAC with moderate specific surface area and pore volume to produce T-WOAC. Alkaline conditions benefitted the photodegradation of CV over photocatalysts. This work proposes a possible degradation mechanism of CV and indicates that the fabricated photocatalysts can be used to effectively remove CV from aqueous solutions.