Photocatalytic persulfate activation by highly dispersed nano-TiO₂ supported by silica for efficient carbamazepine degradation

A silica-loaded nano-TiO2 composite (A-SiO2/TiO2) was prepared by wet-grinding method, using industrial silica (A-SiO2) as the carrier. A-SiO2/TiO2 was used for photocatalytic activation of peroxymonosulfate (PMS) to degrade carbamazepine (CBZ). The A-SiO2/TiO2 containing 20 wt% nano-TiO2 resulted in the CBZ degradation efficiency of 94.83 % after 90 min simulated sunlight irradiation with the presence of PMS. The main reactive species during CBZ degradation in the system of photocatalytic PMS activation by A-SiO2/TiO2 were O-2(center dot-), center dot OH and SO4 center dot-. Compared to nano-TiO2, A-SiO2/TiO2 exhibits enhanced dispersion, increased surface active sites and improved photo-generated carrier separation efficiency, which contributed to enhanced degradation performance.