Superior decontamination of toxic organic pollutants under solar light by reduced graphene oxide incorporated tetrapods-like A_(g3)PO_4/MnFe_2O_4 hierarchical composites;

摘要

To fabricate an efficient, eco-friendly and stable photocatalyst, the current work describes a demonstration of simple synthesis approach of A_(g3)PO_4/MnFe_2O_4(x wt%)/reduced graphene oxide composites. A_(g3)PO_4/MnFe_2O_4 (5 wt%) revealed superior activity for decontamination of dye pollutant. Further, rGO was incorporated with A_(g3)PO_4/MnFe_2O_4 (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 A_(g3)PO_4 varied significantly from orthorhombic dodecahedrons to tripods and tetrapods with the combinations MnFe_2O_4/ (5 wt%), and MnFe_2O_4 (5 wt%)+rGO respectively. The photo-catalytic decontamination of toxic organic dyes tested against Rhodamine B(RhB) and 4-Nitrophenol. The outstanding performance for decontamination of RhB was observed for A_(g3)PO_4/MnFe_2O_4(5 wt%)/rGO (—99% in 5 min) with the rate of k = 7.28 x 10~(-1) min~(-1). The enhanced activity of A_(g3)PO_4/MnFe_2O_4(5 wt%)/rGO composites credited to co-catalytic effects of MnFe_2O_4 and physiochemical properties of rGO which leads to making intimate contact with A_(g3)PO_4 to form heterojunction and rGO served as a medium for charge transfer to prevent their recombination. The incorporation of rGO in A_(g3)PO_4/MnFe_2O_4 (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 A_(g3)PO_4/MnFe_2O_4(5 wt%)/rGO hierarchical composite was evaluated by replicated photocatalytic reaction trials. Overall, the morphological transformation of A_(g3)PO_4/MnFe_2O_4(5 wt%)/rGO composites played a dynamic role in determining their photocatalytic activity towards the organic industrial dye pollutants.