Enhanced electrocatalytic activity of a polyoxometalates-based film decorated by gold nanoparticles

A K6P2MoW17O62-based film decorated by gold nanoparticles was prepared by layer-by-layer self-assembly method. It was fabricated on quartz, silicon and ITO substrates in a progressive and uniform manner monitored by UV-vis spectroscopy, and characterized by atomic force microscopy (AFM), cyclic voltammograms (CVs) and electrochemical impedance spectra (EIS). A set of experimental results revealed that the incorporation of Au nanoparticles into K6P2MoW17O62-based film enhanced the conductivity of the film, leading to several or more than tenfold increase in electrocatalytic efficiency of this film for reduction of H2O2, IO3-, NO2- compared to the no use of Au nanoparticles. It also has been found that presence of Au nanoparticles endowed the film electrocatlytic activity towards oxidation of ascorbic acid and the photo-luminescence property arising from inter electron transitions between occupied 5d bands to 6sp conduction bands of AuNPs.