Biogenic plant decorated synthesis of (Cu,Fe)-ZnO/g-C3N4 heterostructures catalysts by one-step calcination method for degradation of dye pollutants

The shaddock peel, as a plant-mediated regulator, biogenic plant decorated (Cu, Fe)-ZnO/g-C3N4 heterostructures composite was prepared as a novel catalyst using the green approach towards degradation of dye. Both Cu/Fe, ZnO and g-C3N4 were successfully anchored via a one-step calcinated annealing process. The catalytic efficiency of the composites was assessed by measuring the UV–vis absorption spectra of dye. The Cu-ZnO/g-C3N4 composites, obtained through calcination at 550 ℃, exhibited the highest photocatalytic properties, achieving a remarkable 98 % degradation of methyl blue in just 45 min. These synthetic catalysts are suitable for application in natural water bodies and the treatment of diverse organic pollutants. The fabricated composite was meticulously characterized by FTIR, XRD, SEM, UV–vis spectroscopy, BET surface area, and transient photocurrent response, ESR and so on. The results showed Cu acts as an electron mediator, facilitating charge transfer in the Cu-ZnO/g-C3N4 heterostructure. The interface of the composite facilitated efficient separation of electron-hole pairs, which played a crucial role in enhancing dye degradation. Hydroxyl radicals and holes served as the primary reactive species, offering a promising and environmentally friendly approach for the treatment of dye pollutants.