Ag nanoparticles decorated composite assembly for catalytic antibiotics degradation in a fixed-bed reactor

Abstract

The excessive release of antibiotics into the environment poses significant threats to both ecosystem stability and human health. Although persulfate-based advanced oxidation processes show promise for effective antibiotic degradation, their practical implementation faces several challenges, including metal leaching, long-term durability, and high oxidant consumption. This work presents the fabrication of a composite assembly with Ag nanoparticles decorated on reduced graphene oxide-polyurethane foam (Ag/PUF@RGO) via a facile, reductant-free hydrothermal method. The as-synthesized Ag/PUF@RGO catalyst features a three-dimensional, porous, and resilient framework, well-dispersed metallic Ag nanoparticles (average size: 6.1 nm) decoration. When utilized as a structured catalyst and integrated into a fixed-bed reactor, the catalytic system achieved exceptional efficiency for antibiotics and organic dyes degradation via peroxymonosulfate activation under continuous-flow operation. This system also exhibits broad pH adaptability (pH 3–11), favorable anions tolerance, satisfied long-term stability (60 h), and good substrate generality (three antibiotics and four organic dyes). Mechanistic studies reveals that hydroxyl radical is the dominant active specie in the catalytic TC degradation process. The synergistic integration of the active Ag nanoparticles, adsorptive graphene RGO sheets, and resilient PUF substrate in Ag/PUF@RGO composite assembly catalyst with the fixed-bed configuration overcomes mass transfer limitations, minimizes oxidant usage, and prevents secondary pollution, offering a durable and sustainable strategy for water purification.