Copper-Based Metal–Organic Framework (MOF) Photocatalyst Immobilized on Glass Beads for Sustainable Removal of Ciprofloxacin from Water

Abstract

One of the many applications of metal–organic frameworks (MOFs) is their use as adsorbents for removing emerging contaminants, such as ciprofloxacin (CIP), a fluoroquinolone-class antibiotic, from aqueous environments. We selected the copper-based MOF HKUST-1 and coupled it with TiO2, then immobilized the composite on glass beads (TiO2/HKUST-1@GB) to produce a reusable photocatalyst. The immobilization of the composite on glass beads improved the structural strength as well as the reusability of the photocatalyst. Together, these properties pave the way for scale-up for commercial applications in continuous-flow water treatment systems. Herein, we used XRD, FTIR, and SEM to characterize the immobilized catalyst and assess its structural, morphological, and optical properties. Photocatalytic experiments showed 98% degradation in 45 min under UV irradiation at pH 6 and a CIP concentration of 200 μgL−1. The TiO2/HKUST-1@GB composite showed higher degradation compared to pristine TiO2 and HKUST-1 due to enhanced charge–carrier separation and synergistic interfacial effects. The reusability of the composite over five cycles was observed, with high stability and negligible Cu and Ti leaching, indicating promising environmental performance. Thus, TiO2/HKUST-1@GB provides an efficient and sustainable approach for removing ciprofloxacin from aqueous solutions. The degradation performance, reusability, and ability to work simultaneously in adsorption and photocatalytic processes make TiO2/HKUST-1@GB a promising candidate for the advanced treatment of aqueous-phase antimicrobial compounds such as ciprofloxacin.