Synthesis of graphene-based CdS@CuS core-shell nanorods by cation-exchange for efficient degradation of ciprofloxacin

Reduced graphene oxide (RGO) supported CdS@CuS core-shell nanorods (CdS@CuS/RGO) were prepared by a simple, solvothermal method involving cation-exchange for efficient degradation of the fluoroquinolone antibiotic, ciprofloxacin (CIP). CdS@CuS/RGO delivers superior photocatalytic degradation of CIP in simulated sunlight. Ascribed to the unique nanostructure, the CIP degradation efficiency of CdS@CuS/RGO reaches 91.5%, which is higher than that of CdS (67.1%) alone. Compared with previously reported catalysts, CdS@CuS/RGO exhibits higher degradation efficiency in less time and lower dosage. Furthermore, its degradation efficiency remains at around 81.5% after five usage cycles, which represents excellent cycling stability. Free radical scavenging experiments show that superoxide radicals and holes play important roles in the degradation. The CdS@CuS/RGO utilizes the synergistic effects of CdS, CuS and RGO to effectively retard the photo corrosion of CdS upon visible light exposure, reduce the band-gap energy, suppress the recombination of photo-generated electron-hole pairs and promote the adsorption of catalyst toward CIP, thereby, enhancing the catalytic performance of the composite. (C) 2021 Elsevier B.V. All rights reserved.