CdS QDs interspersed onto MOF-808 as adsorptive photocatalyst for efficient visible-light driven degradation of ciprofloxacin

Abstract

CdS Quantum dots (QDs) anchored onto the surface of MOF-808 (hereafter designated as CdS QDs@MOF-808) were constructed by solvothermal method and applied for degradation of ciprofloxacin (CIP) under visible light irradiation. The impacts of pH values and initial concentrations of CIP on adsorption and photocatalytic activity were explored in detail. The as-prepared CdS QDs@MOF-808 composites showed enhanced synergistic adsorption capacity and photocatalytic properties, especially for the CM-20 sample with 20 % CdS QDs loading exhibiting about 5.2 times adsorption capacity (130 mg/g) and approximately 5.5 times photocatalytic removal rate ( 82 %) for CIP compared with the pristine CdS and MOF-808. Various techniques such as XPS, UV‐vis DRS, Zeta potential, EIS, PL as well as transient photocurrent responses have demonstrated that the synergistic effect of CdS QDs and MOF-808 is ascribed to the enhanced electrostatic interactions and Zr-S forces, improving the utilization of visible light and effectively photogenerated electrons transported from the conduction band of CdS to that of MOF-808. Gas chromatography-mass spectroscopy (GC-MS) was used to detect the possible intermediates in the degradation process of CIP.