The preparation of amorphous TiO2 doped with cationic S and its application to the degradation of DCFs under visible light irradiation

Abstract An amorphous S-doping TiO 2 catalyst [S-TiO 2 (300)] with visible light catalytic activity was successfully prepared via a sol-gel method with low-temperature calcination (300 °C) using thiourea as the sulfur source. The S-TiO 2 (300) catalyst showed great performance in degrading the recalcitrant pharmaceutical, diclofenac (DCF). 93% of the target pollutant DCF degraded in 4 h under visible light irradiation. Both the amorphous form of the catalyst and cationic S-doping (with a coordinated structure) contributed to narrowing the band gap. As a result, the photocatalytic activity of S-TiO 2 (300) was significantly enhanced under visible light irradiation. In addition, oxidative species such as photogenic cavitation (h+), OH and O 2 − were proved to participate in the photodegradation process, attacking COOH group and N H bond, degraded DCF into low molecule organic gradually.