Fabrication Of Graphene-Pt@Au Nanocomposite Film And Its Application For Electrocatalysis

Owing to the unique physical, mechanical and chemical properties ofgraphene,Graphene-based composites usually exhibit outstanding performance asfunctional materials in many application fields.However,very few research aboutgraphene prepared by vapor deposition as a catalytic support has been reported.So it’ssignificant to explore the effective graphene-based catalyst materials.Nanoporous gold iswidely used in many areas, and especially as catalyst carrier for methanol oxidation in fuelcells. In this work, we invent a novel catalyst which is composed of graphene andplatinum-nanoporous gold. Compared with platinum-nanoporous gold, it shows greatimprovement in catalytic property.1. Nanoporous gold (NPG) with large surface made from the membrane material ofgold and silver alloy which is only100nm thick by a simple dealloying method.Nanoporous gold (NPG) can be catalyst carrier for platinum nanoparticles which is used inthe Catalysis for methanol oxidation. Under different deposition time, morphologies ofplatinum nanoporous gold are Obtained. XRD analysis confirmed that platinum particleshave been deposited on nanoporous gold. By cyclic voltammetry we measured thecatalytic effect of platinum. And found the optimal synthesis conditions for catalysis.2. By chemical vapor deposition method, we fabrecated three different degrees ofdefective grapheme. And by scanning electron microscopy and optical microscopy tocharacterize the morphology of graphene. we clearly see the different degrees of defects ingraphene. In order to determine the extent of defects in these three kind. of graphene,Raman spectroscopy is used to analyze.3. The composite materials which are made of platinum nanoporous gold andgraphene was used in the catalysis for oxidation of methanol. We found that the catalyticeffect of the composite was greatly improved compared with the platinum nanoporousgold. It must be emphasized that the graphene here we used have moderate defects. Thisgraphene moderately improved catalysis of platinum nanoporous gold. To investigate howthe defects on graphene affecting the catalysis, we prepared three different levels ofdefects. The results showed that too many or few defects were not good at improving the catalysis for oxidation of methanol. Therefore, it is concluded that the graphene withmoderate defects is the desired graphene. To investigate the effect of graphene layers onthe catalysis, we transferred diferent layers of graphene onto the platinum nanoporousgold. The results showed that two layers of graphene is the best.