Electrochemical post-treatment of bimetallic-ICP/RGO precursor for Z-scheme CuOx·Ag2O/RGO hetero-structure with catalytic activity enhancement for visible-light-driven photo-Fenton degradation of tetracycline

Abstract

In this work, rationally designed bimetallic infinite coordination polymer (ICP) was mixed with reduced graphene oxide (RGO) to serve as precursors for the preparation of CuOx·Ag2O/RGO hetero-structure. As the growth of metal oxide nuclei within the ICP network was restricted and more surface-oxygenated species of RGO were exposed during the electrochemical post-treatment process, the CuOx·Ag2O NPs supported on RGO were evenly-distributed nanoparticles with ultra-small size (2.89 ± 0.37 nm), which exhibited excellent catalytic activity enhancement in visible-light-driven photo-Fenton degradation of the model antibiotic tetracycline (TC). Moreover, since the CuOx·Ag2O/RGO was in-situ decorated on ITO glass, recycling of the catalysts with long-term stability could be realized, even after 5 cycles, 91.4 % of TC (10 mL, 50 mg/L) could be degraded within 60 min. A series of characterization and experiment results demonstrated the improved catalytic performance of CuOx·Ag2O/RGO for photo-Fenton degradation was stemmed from the synergistic effect of the components within the catalyst, which facilitated solar energy absorption, accelerated the separation of photo-generated hole-electron pairs through Z-scheme charge transfer way, and strengthened their mechanical stability on the substrate. This newly created catalysts for photo-Fenton reaction are of great potential to achieve the practical treatment of antibiotics-contaminated wastewater.