Unveiling the synergistic interface effects of Ag-deposited Fe2O3/biochar catalysts to enhance wastewater degradation

Abstract

Photo-Fenton reaction is a sustainable and cost-effective wastewater treatment strategy capable of removing persistent organic pollutants. We utilized biochar (referred to as C) as a key component to enhance catalytic efficiency. Using a biomimetic templating method, we synthesized Fe₂O₃ on the biochar and deposited Ag on its surface, resulting in the Ag@Fe₂O₃/C composite material (referred to as AFC). In the photo-Fenton system, the AFC material achieved a 99% degradation rate of methylene blue (MB) within 30 minutes, which is 8.5 times and 6.4 times higher than that of photocatalysis and Fenton reaction alone, respectively. Using Escherichia coli as a model, AFC achieved a 100% bactericidal rate within 6 minutes in the photo-Fenton system. This material effectively treated aquaculture wastewater, removing most impurities and colorants. By introducing Ag nanoparticles as electron transfer centers, the electron transfer efficiency was enhanced, accelerating the catalytic reaction and improving the composite's adsorption capacity for H₂O₂ and organic pollutants. Analysis revealed the migration pathways of photogenerated electrons and holes in AFC, providing a theoretical foundation and practical direction for the design of future photocatalytic materials and the treatment of organic pollutants.