Facile Solid-State Synthesis of Ag/g-C3N4 Reinforced Graphene Oxide for Enhanced Electrocatalysis of Oxygen Reduction Reaction in Alkaline Fuel Cell

Here, we report a rudimentary simple solid-state heat treatment route for the synthesis of graphene oxide (GO) reinforced with silver nanoparticles decorated graphitic carbon nitride (Ag/g-C3N4) to develop an efficient Ag/g-C3N4@GO electro-catalyst for oxygen reduction reaction (ORR). The reinforcement of GO dramatically enhances the electro-catalytic activity of the Ag/g-C3N4 composite material by increasing the conductivity of the low conducting g-C3N4 base material. Thorough characterization of the as prepared material by XRD, SEM, TEM, Raman, EDX and electrochemical techniques confirms that Ag nanoparticles decorated g-C3N4 matrix is homogeneously reinforced with the GO. The electro-catalyst demonstrate excellent ORR activity following four electron pathway with lower onset potential and higher limiting current density as compared to the several other reported Ag-based nanostructured materials including Ag NPs supported on Vulcan carbon. The continuously decreasing Tafel slope (from 154mV/dec for g-C3N4 to 117mV/dec for Ag/g-C3N4@GO) and increasing exchange current density (from 6.46 x 10(-8) Acm(-2) for g-C3N4 to 1.58 x 10(-5) Acm(-2) for Ag/g-C3N4@GO) suggests the much facile electrodics on the surface of Ag/g-C3N4@GO modified electrodes than that of g-C3N4 and Ag/g-C3N4. Furthermore, the catalyst shows excellent methanol tolerance activity and electrochemical stability towards long term applications.