Electrochemically Synthesized Ni@reduced Graphene Oxide Composite Catalysts for Hydrogen Evolution in Alkaline Media – the Effects of Graphene Oxide Support

摘要

Graphene-based materials and their role in electrocatalysis related to hydrogen production have beenintensively investigated by many authors, often justified through a low price of such materials. In thisstudy we used single-step electrodeposition/graphene oxide reduction route to prepare Ni@reduced-graphene-oxide composites for electrochemical hydrogen evolution reaction (HER). As the precursorsfor reduced graphene oxide, two different home-made graphene oxides were used. When compared topure electrodeposited Ni, composite catalysts show improved catalytic activity which depends on Nielectrodeposition time in a volcano-type fashion. Using electrochemically prepared graphene oxide,HER overvoltage needed to reach 10 mA cm ?2 was reduced to only ?97 mV, showing theimprovement by roughly 200 mV when compared to pure electrodeposited Ni. It was concluded thatstructural disorder and surface oxidation of graphene-based materials are the key properties forreaching high HER activities of such prepared catalysts. Based on this observation, it was discussedwhether it is economically justified to use high quality graphene oxide for the preparation of HERcatalysts, as the price (production and commercial) of this material can be extremely high, oftenexceeding the price of platinum.