An α-K3PMo3W9O40 film loaded with silver nanoparticles: Fabrication, characterization and properties

A composite film consisting of the mixed-addenda Keggin-type polyoxometalate α-K3PMo3W9O40 (PMo3W9) and silver nanoparticles (AgNPs) was fabricated on quartz, silicon, and ITO by the layer-by-layer self-assembly method. The regular growth of the multilayer film was monitored by UV–vis spectroscopy, and the morphology was measured by atomic force microscopy (AFM). The multilayer film embedded by AgNPs exhibited the photo-luminescence ascribed to electronic transitions from excited states to d levels of the silver nanoparticles. The composite film also showed electrocatalytic activity towards reduction of NO2−, H2O2, ClO3−, BrO3−, and IO3− attributed to tungsten-centered and molybdenum-centered redox processes of PMo3W9.