Sonochemical decoration of palladium on graphene carpet for electrochemical methanol oxidation

Abstract

• Decoration of palladium nanoparticles on graphene carpets (Pd/rGO) via low-frequency ultrasonication. • Investigate Pd/rGO as an electrocatalyst towards methanol oxidation. • Pd/rGO shows a higher activity of 51.68 mA cm −2 than commercial Pd/C catalyst. • Pd/rGO shows better stability not only in the initial state but also after the 3600 s. Fuel cells can be considered an effective and sustainable energy source to overcome the upcoming energy crisis. Among other fuel cells, Direct Methanol Fuel Cell (DMFC) attained great attention due to ease in storage and transportation along with the high volumetric energy density of methanol. The application of nanomaterials with unique morphologies and properties towards electrochemical methanol oxidation are being intensively studied to improve efficiency. Noble metals and their composites are generally considered the best candidates as electrode materials for methanol oxidation. In this work, a green strategy for the decoration of palladium nanoparticles on graphene carpets (Pd/rGO) has been proposed using glucose as a reducing and stabilizing agent through the aid of ultrasonication. As prepared material was properly analyzed with suitable analytical instruments. The electrochemical performance of the composite was investigated as an electrocatalyst towards methanol oxidation using Cyclic Voltammetry (CV) and Chronoamperometry (CA) techniques. A comparative study of the electrocatalytic activity towards methanol oxidation was carried out among as-prepared Pd/rGO, palladium nanoparticles (Pd NPs), and commercially available palladium on carbon (Pd/C) catalysts Among other samples, Pd/rGO shows a higher activity of 51.68 mA cm −2 during the electrooxidation of methanol than the individual and the commercial. Further, the long-term assessment also shows Pd/rGO has better stability not only in the initial state but also after the 3600 s.