Regresar

Efficient visible-light degradation of Nicosulfuron using a LDH/MOF@Biomass nanohybrid via one-step synergistic adsorption-photocatalysis

Abstract:

The design of visible-light-responsive photocatalytic nanohybrids is emerging as a highly promising strategy for advanced water‐remediation technologies. In this work, a LDH/MOF@Biomass compound was synthesized by coprecipitation and solvo-thermal treatment. Comprehensive characterization (SEM, TEM, BET, XRD, XPS, FTIR) confirmed a well-integrated layered architecture, whose bandgap was reduced to 1.55 eV through the synergistic coupling of MIL-53(Al) crystallites with Mg/Fe anchoring sites. Under a conventional two-stage protocol (dark adsorption followed by photocatalytic irradiation), the material conformed to the Sips isotherm and pseudo-second-order kinetics, delivering a maximum adsorption capacity of 12 mg·g−1 and subsequently achieving 95 % removal of 50 mg·L−1 nicosulfuron (NCS) within 120 min. By contrast, a one-step adsorption–photocatalysis configuration achieved complete NCS elimination (< 60 min) under simulated sunlight (750 W·m−2), following pseudo-first-order kinetics with an apparent rate constant of 0.15 min−1. The catalyst retained ≥ 97 % of its initial activity over five successive cycles, with total metal leaching below 1 mg·L−1 (ICP-OES). Radical-scavenging experiments identified hydroxyl radicals (•OH) as the dominant reactive species, while phytotoxicity assays with Brassica oleracea radicles recorded a 53 % reduction in toxicity relative to untreated NCS solutions. Collectively, these findings establish MgFe-LDH/MIL-53(Al)@HC as a cost-effective, recyclable, and energy-efficient photocatalyst for the rapid abatement of sulfonylurea herbicides and structurally related contaminants in aquatic environments.