Construction of immobilized CuS/TiO2 nanobelts heterojunction photocatalyst for photocatalytic degradation of enrofloxacin: synthesis, characterization, influencing factors and mechanism insight

Abstract

AbstractBACKGROUNDNumerous antibiotics are consumed and excreted to the natural environment by humans and animals, which can cause considerable water pollution. There is strong demand to find an efficient and inexpensive photocatalyst to remove antibiotics effectively from contaminated water.RESULTSHere, CuS/TiO2 nanobelts (NBs) heterojunction photocatalyst immobilized on a titanium foil substrate was constructed. The morphology, structure, composition, optical, and electrochemistry characteristics were explored by corresponding characterization methods. The CuS/TiO2 NBs exhibited enhanced photocatalytic activity for the photocatalytic degradation of antibiotic enrofloxacin (ENR) under simulated solar light illumination. The outstanding photocatalytic performance of as‐prepared composite is attributed to not only the improvement of visible light harvest but also the enhanced separation and transfer efficiency of photoinduced charge carriers. Results showed that the presence of some anions produced a negative effect on the photocatalytic degradation of ENR. The photocatalytic degradation efficiency of ENR followed the order: no anion > Cl− = HCO3− > SO42− > NO3−. The photocatalytic degradation of ENR was restrained in the presence of HA, however, the addition of hydrogen peroxide (0.05 mmol L−1) or application of extra electric field (1.5 V) resulted in an improvement in degradation of ENR. Active species trapping experiments confirmed that the superoxide radical (•O2−) is the major oxidant species and the holes (h+) and hydroxyl radical (•OH) are the minor active species. A possible heterojunction photocatalytic mechanism was proposed. Furthermore, CuS/TiO2 NBs heterojunction photocatalyst has excellent photocatalysis stability.CONCLUSIONSThis novel visible‐light responding CuS/TiO2 NBs heterojunction photocatalyst would be a promising candidate material for antibiotic elimination from water. © 2019 Society of Chemical Industry