PHOTOCATALYSIS COUPLED WITH OXIDANTS FOR THE ENHANCED DEGRADATION OF CARBAMAZEPINE

Abstract

The rapid recombination of electron-hole pairs in excited photocatalysts imposes a significant limitation on the efficiency of photocatalytic processes. Powerful oxidants were found to be good electron acceptors for photocatalysis. In this study, the synergistic effect of coupling photocatalytic process with oxidants were quantitatively investigated. Meanwhile, the impact of water matrix on the coupled system was systematically investigated. The formation of brominated oxidation byproducts in the oxidant-enhanced TiO2-based system was also studied. Moreover, the analysis of the interactions between anions and photocatalysts were conducted based on the density functional theory to provide an in-depth explanation of the mechanism behind the effect of water matrix. The results indicate that oxidants (persulfate and free chlorine) inhibited the recombination of electron-hole pairs in the excited TiO2 and a synergistic effect was achieved. Persulfate induced the bromate formation in the UVA/TiO2 system. Adsorption energy indicates spontaneous adsorption processes for bicarbonate and persulfate on TiO2.