Solar photocatalytic abatement of tetracycline over phosphate oxoanion decorated Bi2WO6/polyimide composites

Environmental-friendly solar photocatalytic technology is attracting great attention in the field of pollution control. In this work, novel PO 4 3− -Bi 2 WO 6 /PI photocatalyst achieved high degradation efficiency for tetracycline degradation in simulated solar light (1.6 times kinetic constants of Bi 2 WO 6 ). The photocatalyst could produce more oxygen vacancies as well as more active species O 2 − 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 3 − can accelerate the tetracycline degradation. The degradation of tetracycline by PO 4 3− -Bi 2 WO 6 /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.