Carbon nanotube and graphene oxide directed electrochemical synthesis of silver dendrites

Abstract

We report a simple one-step electro-deposition method for the synthesis of silver dendritic structures with the aid of graphene oxide (GO) modified multi-walled carbon nanotubes (MWCNTs) which are dispersed in an AgNO₃ solution. Scanning electron microscopy indicated that the formed silver material had a well-defined dendritic structure and XRD confirmed that the silver was in a cubic phase. UV-vis spectroscopy indicated the presence of GO in the silver dendrites which was electrochemically reduced during the silver electro-deposition process. It was found that the presence of MWCNT is crucial for the formation of the dendrite structure of the deposited Ag. The concentration of AgNO₃ and the electrochemical deposition cycles also had significant effects on the shape of the formed nanostructures. A possible growth mechanism for the Ag dendrites was proposed based on the experimental results. In addition, the electro-catalytic properties of the as-prepared silver dendrites towards the reduction of hydrogen peroxide were investigated by cyclic voltammetry. The results showed that Ag dendrites prepared in the presence of MWCNT and GO had a higher electro-catalytic activity than silver materials prepared with only either MWCNT or GO.