Efficient photocatalytic degradation of commercial pharmaceutical contaminants of carbamazepine using BiOBr nanosheets under visible-light irradiation

Abstract

Removing pharmaceutical contaminants is the growing concerns for the public people. Herein, commercial pharmaceutical drug of carbamazepine (CBZ) was degraded by photocatalysis. Highly efficient visible-light-driven BiOBr nanosheets were fabricated using water mediated hydrolysis route with the assistment of tetra (n-butyl) ammonium hydroxide (TBAOH). In particular, BiOBr nanosheets prepared with 0.1 mmol TBAOH (0.1 mmol TBAOH + KBr) performed the optimum photocatalytic degradation activity, enabling 88.7% removals of CBZ after 20 min irradiation under visible-light. Furthermore, 0.1 mmol TBAOH + KBr BiOBr nanosheets displayed fast degradation kinetics, with a degradation rate constant of 6.2 times than BiOBr prepared without TBAOH (0 mmol TBAOH + KBr). The enhanced photocatalytic activity was originated from the improvement of adsorption performance, photo absorption, and separation rate of photoinduced electron-hole pair. The major active species participated in CBZ degradation were proved to be h+, •O2-, and •OH using quenching experiments. The present results can throw light on the development of visible-light-driven photocatalyst with considerable catalytic activity for removing pharmaceutical contaminants.