Layer-by-layer assembly of chitosan/tungstosilicate acid-Ag nanocomplex with electrocatalytic properties

Abstract

Tungstosilicate acid (TSA)-Ag nanocomplex were synthesized based on the reduction of silver nitrate by UV-irradiated tungstosilicate acid solution. The nanocomposite films consisting of TSA-Ag composite nanoparticles and chitosan (CTS) were fabricated by layer-by-layer self-assembly technique. The coverage degree of TSA-Ag composite nanoparticles on the surface of the film increased with the number of the bilayers. TSA-Ag composite nanoparticles grew in a direction normal to the surface of the film. Large overlap existed between adjacent layers of TSA-Ag and CTS. The composite thin film exhibited linear, uniform and regular layer-by-layer growth. The multiplayer films exhibited good electrocatalytic activity for dioxygen reduction.