Design of Bi4O5Br2/g-C3N4 heterojunction for efficient photocatalytic removal of persistent organic pollutants from water

Dyes and antibiotics as typical persistent organic pollutants (POPs) are widely present in the environment, but can hardly be removed completely by traditional water treatment methods. Here, we designed Bi₄O₅Br₂/g-C₃N₄ composite nanosheets for efficient photocatalytic removal of POPs in water. The Bi₄O₅Br₂/g-C₃N₄ composite with a heterojunction structure exhibited high adsorption and photocatalytic activity for removal of tetracycline (TC) and ciprofloxacin (CIP) with excellent cyclic stability, owing to its large specific surface area as well as enhanced charge separation and visible light utilization. Our characterization revealed that h⁺ and ·OH are responsible for the photocatalytic degradation of TC and CIP. This work provides insights into the design of photocatalytic materials with synergy of adsorption and photocatalytic degradation, and offers a heterojunction construction strategy for addressing the increasingly severe environmental issues.