Superior decontamination of toxic organic pollutants under solar light by reduced graphene oxide incorporated tetrapods-like Ag3PO4/MnFe2O4 hierarchical composites

Abstract To fabricate an efficient, eco-friendly and stable photocatalyst, the current work describes a demonstration of simple synthesis approach of Ag3PO4/MnFe2O4(x wt%)/reduced graphene oxide composites. Ag3PO4/MnFe2O4 (5 wt%) revealed superior activity for decontamination of dye pollutant. Further, rGO was incorporated with Ag3PO4/MnFe2O4 (5 wt%) to investigate its effect on their overall properties. The resultant composites were characterized by various analytical techniques to confirm their structural and physical-chemical features. FESEM analysis showed that morphology of Ag3PO4 varied significantly from orthorhombic dodecahedrons to tripods and tetrapods with the combinations MnFe2O4 (5 wt%), and MnFe2O4 (5 wt%)+rGO respectively. The photocatalytic decontamination of toxic organic dyes tested against Rhodamine B(RhB) and 4-Nitrophenol. The outstanding performance for decontamination of RhB was observed for Ag3PO4/MnFe2O4(5 wt%)/rGO (~99% in 5 min) with the rate of k = 7.28 × 10−1 min−1. The enhanced activity of Ag3PO4/MnFe2O4(5 wt%)/rGO composites credited to co-catalytic effects of MnFe2O4 and physiochemical properties of rGO which leads to making intimate contact with Ag3PO4 to form heterojunction and rGO served as a medium for charge transfer to prevent their recombination. The incorporation of rGO in Ag3PO4/MnFe2O4 (5 wt%) composite leads to a considerable increase in the photocatalytic activity by offering improved surface area and properties, high electron stability and mobility. Based on experiment results, the photocatalytic enhancement mechanism for organic pollutants degradation was discussed. The recyclability of Ag3PO4/MnFe2O4(5 wt%)/rGO hierarchical composite was evaluated by replicated photocatalytic reaction trials. Overall, the morphological transformation of Ag3PO4/MnFe2O4(5 wt%)/rGO composites played a dynamic role in determining their photocatalytic activity towards the organic industrial dye pollutants.