In situ synthesis of a nanoplate-like Bi-based heterojunction for photocatalytic degradation of ciprofloxacin

A nanoplate-like Bi-based heterojunction was firstly prepared through in situ formation of Bi2S3 nanocrystals on the surface of BiOBr nanoplates via a facile anion exchange strategy. The as-prepared Bi2S3/BiOBr heterojunctions were carefully characterized by multiple physicochemical techniques. The photocatalytic activity of as-synthesized samples were evaluated by the photodegradation of ciprofloxacin (CIP) under visible-light irradiation (lambda > 420 nm). Compared to the pristine BiOBr, the Bi-based heterojunctions exhibited dramatically enhanced photocatalytic activity towards the CIP degradation in aqueous solution. Moreover, it is found that the 4% Bi2S3 coupled BiOBr heterojunction showed the superior photoreactivity for removal of CIP, which is about 2.8-folds higher than that of pure BiOBr. The significantly improved photoactivity was ascribed to the effective separation of photogenerated electron-hole pair's between the Bi2S3 and BiOBr. This work highlights a simple approach to design the Bi-based nanocomposites and develops an efficient visible-light-driven heterojunction material for application in antibiotic pollutant purification. (C) 2017 Published by Elsevier B.V.