Construction of chitosan‑functionalized Zn‑MOFs for enhanced photocatalytic antibiotic removal in water treatment

CS@Zn-MOFs were synthesized via a facile coordination-driven coating method. • The composite shows enhanced colloidal stability and uniform element distribution. • It achieves 91.61% MB removal and high ROS generation under light irradiation. • Effective TC (88.78%) and EM (89.44%) removal via adsorption and AOPs. • Excellent recyclability, stability, high TOC removal, and low cytotoxicity for water treatment. The widespread presence of antibiotics in aquatic environments poses serious ecological and health risks due to their persistence and potential to promote antibiotic resistance. Conventional water treatment processes often fail to remove these micropollutants effectively, highlighting the need for advanced and sustainable remediation strategies. In this study, chitosan‑functionalized zinc‑based metal-organic framework (CS@Zn‑MOFs) with a spindle‑like morphology was developed to enhance photocatalytic removal of antibiotics from water. The composite was synthesized through a coordination-driven self-assembly process followed by CS coating. Comprehensive characterization including SEM-EDS, XRD, XPS, and FTIR, confirmed effective structural integration, homogeneous elemental distribution, and improved colloidal stability. Under light irradiation, CS@Zn-MOFs exhibited exceptional photocatalytic activity, achieving 91.61% removal of methylene blue within 120 min and facilitating substantial generation of reactive oxygen species (ROS). The composite significantly reduced residual levels of tetracycline (TC, 88.78%) and erythromycin (EM, 89.44%), demonstrating efficient antibiotic removal through a synergistic combination of adsorption and advanced oxidation processes (AOPs). Furthermore, CS@Zn-MOFs exhibited excellent recyclability and long-term stability across multiple cycles, coupled with high total organic carbon (TOC) removal efficiency and negligible cytotoxicity. These results collectively demonstrate that CS@Zn‑MOFs are an efficient and stable candidate for the photocatalytic remediation of antibiotic‑contaminated water. This illustration summarizes the design, mechanism, and performance of a novel chitosan-coated Zn-MOFs nanocomposite (CS@Zn-MOFs) for water remediation. The spindle-like Zn-MOFs are functionalized with a chitosan coating through hydrogen bonding and electrostatic interactions, enhancing stability and functionality. Under LED light irradiation, the composite generates abundant reactive oxygen species (ROS), which efficiently purify antibiotic pollutants (e.g., tetracycline and erythromycin) via adsorption and advanced oxidation processes. CS@Zn-MOFs exhibit excellent reusability, long-term stability, coupled with high total organic carbon removal efficiency and negligible cytotoxicity, showcasing great potential as a sustainable and effective photocatalytic material for treating antibiotic-contaminated water. Download: Download high-res image (195KB) Download: Download full-size image