Tailored spherical-sea urchin-like MnO₂-AC/PTA nanocomposites for superior photocatalytic degradation of BPA and Orange II dye, along with bacteria Inactivation: Mechanistic insights

In this study, we present a pioneering approach introducing a novel spherical-sea urchin-like MnO₂-KAFC/PTA (Manganese dioxide/KOH activated foam derived carbon/Phosphotugstic acid) nanocomposite photocatalyst for photocatalytic degradation of organic pollutants and bacteria inactivation. It is well-established that the reactivity in photocatalytic applications heavily relies on the shape and crystallographic orientation of the photocatalysts. Thus, we synthesized controllable MnO₂-KAFC/PTA NCs with spherical-sea urchin-like morphologies using the in-situ precipitation method. Subsequently, the synthesized KAFC, MnO₂ NPs, and spherical-sea urchin-like MnO₂-KAFC/PTA NCs were systematically characterized in detail. Following characterization, they were employed as photocatalysts for photocatalytic degradation of Bisphenol A (BPA) and Orange II dye pollutants, as well as for the inactivation of Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). The spherical-sea urchin-like MnO₂-KAFC/PTA NCs photocatalyst demonstrated outstanding photocatalytic degradation efficiency, achieving rates of 99.8% and 99.9% for BPA and Orange II dye, respectively, under sunlight irradiation. Notable, the spherical-sea urchin-like MnO₂-KAFC/PTA NCs exhibited excellent degradation efficiency (99.8 and 99.9%) compared to MnO₂ NPs (40 and 51%), and KAFC (26 and 21%), respectively. Furthermore, the optimized spherical-sea urchin-like MnO₂-KAFC/PTA NCs photocatalysts were subjected to bactericidal testing against E.coli and S. aureus pathogens. The results revealed that the optimal antibacterial efficacy against E.coli and S. aureus microbes was zone inhibition up to 18 mm and 20 mm, respectively. Overall, the present study underscores the efficacy of spherical-sea urchin-like MnO₂-KAFC/PTA NCs as potent antibacterial and degrading agents.