Preparation and characterization of nickel and copper oxide/hydroxide films on stainless steels substrates for use as cathodes in alkaline water electrolysis

摘要

The production high purity hydrogen by water electrolysis based renewable sources as a mean to store energy, has gained some attention in the last years due to the high specific energy of hydrogen, the potentially neutral carbon and zero emission of the usage of H_2 as fuel. However, it remains certainly necessary to develop efficient and lower cost electrolyzers. Such a situation requires the search for and the development of inexpensive and stable electrode materials, showing low polarization to hydrogen evolution reduction (HER). In this work copper and nickel oxides were studied for use as electrodes for the reduction of hydrogen in alkaline water electrolysis. The nickel and copper oxide composites coatings were deposited electrochemically as oxides/hydroxides on a stainless steel (SS) electrode and characterized using electrochemical methods such as cyclic voltammetry (CV), cathodic polarization and Tafel slops. The HER was studied using as electrolytic cathodes unmodified AISI 304 stainless steel (SS), nickel coated stainless steel (SS/Ni), copper coated stainless steel (SS/Cu), and nickel (under layer) and copper (top layer) coated stainless steel(SS/Ni/Cu) in 5 M KOH solution. It was found that, the SS/Ni/Cu electrode presents good electrocatalytic activity and stability toward the HER, compared to the SS electrodes modified by single nickel oxide layer. This behavior seems be explained by the synergistic interaction of Ni and Cu with Fe present in the stainless steel.