Environmentally benign one pot green synthesis of reduced graphene oxide based composites for the enzyme free electrochemical detection of hydrogen peroxide
A simple green protocol was developed for the simultaneous reduction of graphene oxide (GO) and metallic ions for the preparation of reduced GO/mono and bimetallic composites using Arachis hypogaea scrap extract. The highly crystalline and face-centered-cubic structure of monometallic silver (Ag) and bimetallic Ag-palladium (Ag-Pd) nanoparticles with the average particle size of 7 nm were effectively anchored over the rGO sheets as configured from the morphological images. The spherical morphology, average particle size and structure of monometallic Ag and bimetallic Ag-Pd nanoparticles anchored over the rGO sheets maintained identical without the influence of any surfactants and passivating agents. The functional groups involved in the reduction of GO and metallic precursors were identified through the Fourier Transform Infrared spectroscopic analysis. The influences of prepared nanostructures toward enzyme free hydrogen peroxide (H2O2) sensor performances were evaluated under the neutral conditions. The as-fabricated rGO/Ag-Pd/GCE responded linearly to the concentration of H2O2 over a wide range of 0.005 to 14.65 mM and exhibited a sensitivity of 342 μA mM-1 cm-2 and a low level detection limit of 1.1 µM toward H2O2 electrooxidation. Thus the proposed approach has not only showered the salient insights on the preparation of environmentally benign rGO based composites but has also paved the futuristic dimensions of green catalysts in enzyme free H2O2 sensor applications.