Multistrategy Optimization of Benzothiadiazole-Based Ln-MOF Composites for Enhanced Photocatalytic Degradation of Tetracycline

Abstract

Abstract Tetracycline hydrochloride is a common aquatic contaminant and poses significant risks to environmental and human health. However, developing high-performance removal materials with good recyclability remains a challenge. The electron-deficient benzothiadiazole linker endowed these frameworks with visible-light absorption capability, while lanthanide nodes regulated ligand–metal electronic coupling and graphene oxide-mediated interfacial charge transfer, creating efficient photocatalyst composites (Ln-MOFs/GO) for TC degradation. The graphene oxide loading was optimized to obtain Ho/10-GO, which achieved 84.6% degradation of 10 ppm tetracycline (TC) hydrochloride within 40 min under visible-light irradiation after dark adsorption equilibrium had been reached. Encapsulating the composite in sodium alginate gel maintained a high pollutant removal rate over 15 catalytic cycles and enabled simple material recovery. Mechanistic studies combining radical-trapping tests and DMPO-based EPR measurements confirmed the generation of •O2– and indicated that the O2/electron-mediated pathway plays a key role in TC degradation. Structure–property analysis showed that the photocatalytic performance results from the visible-light-responsive benzothiadiazole units and the formation of type II heterojunctions, which improve photogenerated carrier separation. Ho/10-GO@Alg was also applied to visible-light-driven condensation–cyclization synthesis of benzothiazole derivatives. This research provides an effective strategy for TC degradation and offers insights into treating TC contaminants in aquatic environments.

The authors' abstract, as published at the source. Inorganic Chemistry, 2026 · DOI ↗