Effect of polydopamine-modified reduced graphene oxides on the catalytic activity of Pt nanoparticles catalysts for fuel cell electrodes

Abstract

We have studied a method to prepare polydopamine-modified reduced graphene oxide-supported Pt nanoparticles (Pt–PDA–RGO). The Pt–PDA–RGO nanocomposites were synthesized by a wet-coating process, which was induced by self-polymerization of dopamine. As an eco-friendly and versatile adhesive source in nature, dopamine could be easily adhered to surfaces of organic material and inorganic material via polymerization processes and spontaneous adsorption under weak alkaline pH conditions. To apply the unique features of dopamine, we synthesized Pt–PDA–RGO nanocomposites with a different quantity of dopamine, which are expected to preserve the improved Pt adsorption on graphene, resulting in the enhanced electrocatalytic performance. The morphology and micro-structure were examined by field emission scanning electron microscopy, transmission electron microscopy, and Fourier transform infrared spectroscopy. Compared to pristine Pt–deposited RGO (Pt–RGO), Pt–PDA–RGO (30\xa0wt% dopamine against RGO) nanocomposites showed a superior electrochemical active surface area for a methanol oxidation. This could be related to the fact that the optimized content of PDA-coated RGO exhibited a higher electrochemical surface area and better Pt adsorption on the RGO surface.