Preparation of a Carbon Fiber-Nickel-Type Material and Investigation of the Electrocatalytic Activity for the Hydrogen Evolution Reaction

The preparation and the electrocatalytic activity of a new material of the type carbon fiber-nickel was investigated. Nickel growth on the carbon support was can-ied out through electrolysis. The kinetic of nickel deposition as a function of the electrolysis conditions was examined by cyclic voltammetry. The morphology and substitution of the nickel deposits, which at the beginning of the nickel growth proved to be of a globular type, were studied by scanning electron microscopy. It was established that a high degree of the carbon surface functionalization, achieved by double pulse oxidation, favored the nickel deposits on the oxidized carbon support. The electrocatalytic efficiency of nickel-modified carbon fiber electrodes was investigated by means of impedance spectroscopy for the hydrogen evolution reaction. The charge transfer resistance values of this reaction were significantly lower in the case of modified by nickel oxidized carbon fibers in comparison with the corresponding values for modified by nickel pristine fibers. The above values are in the order of magnitude of modified by noble metals, such as Pd and Rd, carbon fibers obtained through ion-exchange with the functional groups of the oxidized carbon fibers, and subsequent electrochemical or chemical reduction.