Electrochemical Properties of Polyoxometalate (H3PMo12O40)-Functionalized Graphitic Carbon Nitride (g-C3N4)

A functionalized polyoxometalate/graphitic carbon nitride (PMo12/g-C3N4) composite has been constructed to promote direct electron and ion exchange based on a facile, rapid wetness incipient method. The PMo12 displayed a natural affinity towards the carbon support which facilitated enhanced reversible redox processes with surface-controlled electron diffusion. The g-C3N4-functionalized PMo12 composite promoted effective oxidation and reduction of the Keggin molecule addenda atoms with reduced overpotential without the mediation of a polymeric linker to promote their exposure and interaction. The g-C3N4 offered increased surface area for anchoring PMo12, structural stability at increased temperatures, and repeated cycling as well as control of the density and position of PMo12 as probed by scanning electron microscopy and nuclear magnetic resonance spectroscopy, respectively. These results demonstrate that PMo12 clusters are sensitive to their local environment, including the interaction with the support, which stimulated enhanced current mobility.