In₂O₃-ZnO nanoporous photocatalyst modified with CuO_x cocatalyst for enhanced photocatalytic bacterial inactivation and dye degradation

In this study, CuO_x surface passivated In₂O₃ loaded porous ZnO, (CuO_x/In₂O₃(x%)-ZnO)), were synthesized utilizing a solvothermally produced organic–inorganic ZnS(en)_0.5 hybrid material. The high-resolution scanning electron microscopy (HR-SEM) and transmission electron microscopy (TEM) images of the CuO_x/In₂O₃(2.5%)-ZnO nanocomposite reveal a macrosheet-shaped morphology comprising nanosized grains. The photocatalytic behavior of all the synthesized CuO_x/In₂O₃(x = 0,1,2.5, and 5%)-ZnO nanocomposites were examined against aqueous dye solutions of orange II, and bisphenol A, E. coli bacteria under one sun illumination. The CuO_x/In₂O₃(2.5%)-ZnO nanocomposite exhibits enhanced photoactivity for cationic dyes (eosin Y) than that for anionic (orange II). The results indicate that cationic dyes undergo photocatalytic degradation, whereas the anionic dyes adsorb on the CuO_x/In₂O₃(2.5%)-ZnO nanocomposite surface, reducing the removal of organic pollutants. The optimal nanocomposites, CuO_x/In₂O₃(2.5%)-ZnO photocatalyst exhibit maximum photodegradation performance of 99%, 94%, 27% for orange II dye, eosin dye, BPA, and 98% for E. coli inactivation within 180 min, respectively. The CuO_x/In₂O₃(2.5%)-ZnO nanocomposite was successfully demonstrated to be an effective photocatalyst and excellent antibacterial agent. Finally, the charge transfer mechanism during photocatalytic organic decomposition and bacterial inactivation was studied.