Solar photocatalytic abatement of tetracycline over phosphate oxoanion decorated BiWO/polyimide composites.

Environmental-friendly solar photocatalytic technology is attracting great attention in the field of pollution control. In this work, novel PO-BiWO/PI photocatalyst achieved high degradation efficiency for tetracycline degradation in simulated solar light (1.6 times kinetic constants of BiWO). The photocatalyst could produce more oxygen vacancies as well as more active species O and OH, and exhibited high mineralization ability, good stability and recyclability simultaneously. After 4 cycles of degradation experiments, its degradation efficiency was only reduced by 8.6 %. Tetracycline molecules gradually became small molecules under the attack of active species. The tetracycline degradation was highly pH-dependent and enhanced with the increase of solution pH. The water quality parameters humic acid and Cl presented the inhibitory effect, while HCO can accelerate the tetracycline degradation. The degradation of tetracycline by PO-BiWO/PI conformed to the Z-scheme photocatalysis mechanism, which could effectively broaden the absorption of solar light, improve the separation and transfer of photogenerated electron-hole pairs and extend the lifespan of the photocatalyst.