PREPARATION OF HIGHLY DISPERSED GOLD MICROPARTICLES AND THEIR ELECTROCATALYTIC ACTIVITY FOR THE OXIDATION OF FORMALDEHYDE

The electrochemical preparation of highly dispersed Au microparticles on the surfaces of glassy carbon (GC) electrodes and their electrocata lytic activities for the oxidation of formaldehyde were studied. It wa s found that the reduction of Au3+ to Au is controlled by diffusion an d the formation mechanism of Au microparticles on the GC surfaces corr esponds to an instantaneous nucleation and diffusion-controlled three dimensional growth process. The particle size is about 80-90 nm in dia meter after the electrochemical ageing treatment. These highly dispers ed Au microparticles have high surface areas and exhibit better electr ocatalytic activity than that of bulk-form Au toward the electrochemic al oxidation of formaldehyde in alkaline media.