Efficient heterostructure of CuS@BiOBr for pollutants removal with visible light assistance

Abstract

The Z-scheme heterojunction photocatalyst CuS@BiOBr was fabricated by precipitating BiOBr on CuS nanoparticles. The experimental results showed that CuS@BiOBr system showed high efficiency in the photocatalytic degradation of ciprofloxacin (CIP) compared with BiOBr and CuS. Catalyst application in realistic wastewater: CIP of removal ratio was 86.49%, 76.95%, 78.58% and 75.11% in DI water, tap water, lake water (longitude123.701077, latitude 41.453335) as well as river water (longitude 123.701710, latitude 41.453070), separately. These results show that CuS@BiOBr-700 can be effectively used for the photocatalytic removal of ciprofloxacin contaminants in the environment. • Composite catalyst of CuS@BiOBr was synthesized through a two-step hydrothermal method. • The CuS@BiOBr exhibited enhanced activity for CIP oxidation under visible-light. • Visible light response enhancement effect of CuS was demonstrated. • Composite catalyst of CuS@BiOBr has superior durability. Constructing the Z-scheme photocatalyst has been seen as an effective strategy to facilitate the removal of antibiotic contamination by photocatalysts. We constructed the Z-type heterojunction photocatalyst CuS@BiOBr by precipitating BiOBr on CuS nanoparticles. The experimental results showed that the CuS@BiOBr in comparison to BiOBr and CuS system exhibited highly efficient photocatalytic degradation of ciprofloxacin (CIP). The degradation rate of CIP under CuS, BiOBr and CuS@BiOBr-700 heterojunction were 19.28%, 53.26% and 86.49%, respectively. The structure, morphology, porosity, optical performance and photoelectrochemical properties of CuS@BiOBr were characterized by multifarious characterization methods. The influence of environmental factors (different water sources and initial pH) on the degradation of ciprofloxacin (CIP) was investigated. A Z-scheme charge transfer mechanism was confirmed by free radical trapping experiments, which demonstrated that the photoexcited holes (h + ) and superoxide radicals (⋅O 2 ¯ ) were the major active species.