Bioinspired silver nanoparticles/reduced graphene oxide nanocomposites for catalytic reduction of 4-nitrophenol, organic dyes and act as energy storage electrode material

Facile and a novel technique for bioinspired synthesis of silver nanoparticles (AgNPs) using an aqueous extract of mango (Mangifera indica) flower as stabilizing and reducing agent was demonstrated. The formation of AgNPs and AgNPs/rGO nanocomposites were confirmed through extensive experimental characterization and numerical analysis. Both, AgNPs and AgNPs/rGO nanocomposites showed excellent catalytic performance in catalytic hydrogenation of 4-nitrophenol and azo bond in dye molecules. The rGO supported Ag nanocomposites exhibited improved catalytic activity compared to AgNPs due to the enhancement of surface area. Electrochemical analysis of AgNPs/rGO nanocomposites showed specific capacitance (SC) of ∼532 F g⁻¹ at a current density of 1.0 A g⁻¹. About 92% retention in SC after 2000 charge-discharge cycles suggested long-term electrochemical cyclic stability as supercapacitor electrode materials. The biogenic nano-particles and composites implied that the rGO reinforced Ag excellent applicants as hydrogenation refining materials. All these observations demonstrated a novel, eco-cost effective and estimable candidates as hydrogenation refining materials and electrode materials.