Polyoxometalate-Mediated Green Synthesis of Graphene and Metal Nanohybrids: High-Performance Electrocatalysts

This report focuses on our recent achievements relevant to the development of facile, green and low cost synthetic approaches leading to high-nuclearity polyoxometalate/graphene (POM/G), POM/poly(ionic liquid)/G, POM-based metal organic framework/G (POMOF/G) and Metal (Ag, Au, Pd, Pt) nano-object/POM/G (Metal/POM/G) hybrids aimed at effective photo-electro-catalysis of challenging reactions. All the synthetic routes yield hybrids with high quality G, improved electrochemical properties, huge surface area, and remarkable stability under various conditions. Well-defined metal nanoparticles were generated for Au, Pd and Pt nanostructures whereas a 2D Ag nanonet was observed for that of Ag. Moreover, the synergistic effect of the three components of these hybrids induces significant enhancement of their electrocatalytic activity. In particular, the Au NPs/POM-G hybrids can be used as remarkably effective enzyme-free biosensor for H2O2. They disclose salient electrocatalytic performance with high sensitivity and selectivity, good long-term stability, large detection range, low detection limit and fast current response for H2O2 detection. Outstanding electrocatalytic activity was also demonstrated for the Ag NN/POM-G hybrids towards the oxygen reduction reaction in alkaline medium. Owing to their higher durability compared to that of commercial Pt/Carbon nanocomposites, the Ag NN/POM-G hybrids are new promising low cost cathode materials for alkaline fuel cells.