Graphene-TiO2 composite supported Pt electrocatalyst for oxygen reduction reaction

A nano-sized Pt catalyst supported onto titanium dioxide functionalized graphene nanosheets (TiO2-FGSs) was prepared using the polyol method and utilized for a catalyst activity investigation toward the oxygen reduction reaction (ORR). The electrochemical and microscopic studies were carried out using a 40 wt.% Pt/TiO2-FGS catalyst. Cyclic voltammetry and the rotating disk electrode experiments were performed in 0.5 M H2SO4 and 0.1 M KOH solutions in order to investigate the electrocatalytic behavior of the prepared catalysts. The composite catalyst samples were characterized by scanning electron microscopy and transmission electron microscopy showing a good dispersion of the Pt particles on the surface of the graphene supported TiO2 particles. The average Pt particle size was 11 ± 2 nm. The values of specific activity and other kinetic parameters were determined from the Tafel plots taking into account the real electroactive area of each electrode. The electrodes exhibited a relatively high electrocatalytic activity for the four-electron reduction of oxygen to water.