Synergistic photocatalytic and antimicrobial efficacy of poly(m-aminophenol)/reduced graphene oxide/cobalt oxide hybrid composite for organic dye degradation.

In this paper, we discuss the fabrication and characterization of a novel composite photocatalyst, poly(m-aminophenol)/reduced graphene oxide/cobalt oxide (PmAP/rGO/CoO), and its incomparable photocatalytic efficacy towards the degradation of cationic dyes under the exposure of visible light. The composite was synthesized via an in situ oxidative polymerization method, utilizing rGO and CoO as templates. The effect of varying rGO/PmAP percentages in the composite on photocatalytic performance was investigated, with 5 wt% rGO/PmAP (PRC-5) emerging as the most effective combination, exhibiting degradation percentages of 95.4% and 94.3% for methylene blue and malachite green, respectively, within 60 min. The enhanced efficiency of the composite was attributable to the increased surface area and reduced cobalt oxide aggregation of nanoparticles, leading to enhanced light absorption. Photoluminescence (PL) spectra and Mott-Schottky data supported the proposed Z-scheme mechanism, which involved the generation of high concentrations of OH radicals, holes (h), and O, as revealed by the active species trapping experiment. Zone of inhibition for the E. coli bacterial strain as indicated by PmAP/rGO/CoO NCs at a concentration of 1000 mg/ml. It became apparent that the synthesized PmAP/rGO/CoO conjunction was a highly effective antibacterial and photodegrading agent. Our findings suggest that the PmAP/rGO/CoO composite holds great promise as an effective alternative for industrial wastewater treatment applications.