Effective and Stable CoNi Alloy-Loaded Graphene for Ethanol Oxidation in Alkaline Medium

Abstract

Low electro-catalytic activity and poor stability are the main dilemmas facing the non-precious electro-catalysts. The super-electric conductivity and marvelous adsorption capacity strongly recommend graphene to enhance the electro-catalytic activity; however the alloy structure distinctly improves both of the catalytic activity and chemical stability for the non-precious electro-catalysts. In-situ decoration of graphene by CoxNiy alloy nanoparticle is introduced to be utilized as an electro-catalyst for ethanol oxidation. Briefly, cobalt acetate and nickel acetate were added to the reaction media during graphene preparation using a modified chemical route. Later on, the resultant material was calcined in argon atmosphere at 850°C. The utilized physicochemical characteristics affirmed formation of multi-layer graphene sheets decorated by solid solution CoxNiy alloy nanoparticle. Influence of the nanoparticles chemical composition and loading on the electro-catalytic activity was investigated. Interesting results were obtained as follow: utilizing graphene enhances the electro-activity to be 10 times more than the pristine nanoparticles, moreover a negative onset potential was obtained (−90 mV vs. Ag/AgCl). Furthermore, the obtained results indicated that the metallic nanoparticle composition and loading have distinct impacts on the electro-catalytic activity; Co0.2Ni0.2-decorated graphene revealed the best performance as well as very good stability.