The Electrochemical Characterization Of The Low Overpotential Nickel And Cobalt Based Functional Materials For Hydrogen Evolution Reaction

Hydrogen evolution reaction is significant to apply to electrochemical energy conversion , electrochemical industry ,metallic corrosion and protection and metal electrodeposition. The cheap electrode materials with good hydrogen evolution catalytic performance can prolong the electrode cycle life ,save energy ,improve profit .So it very important to research on the cathodic materials of high electrocatalytic activity. Electrolytically and electroless deposited Ni films containing alloying elements such an phosphorous and transition mental have been studied extensively due to their unique properties and low price . Of special interest are their catalytic properties towards the hydrogen evolution reaction. Some of the alloys may have up to 1000 times higher reaction rate the rate found on pure nickel. In this paper, low hydrogen evolution overpotential alloys electrodes Co-Ni-W and Ni-Co-W-P and Ni-W-TiO₂ were prepared respectively by electroplating or electroless plating methods. The physical and chemical properties of the electrodes were studied. The main experiments and the results are as following:1. Through orthogonal experiment, the Co-Ni-W alloy electrode was prepared from porous solution. The effects of ions concentration, current density and pH value on electrodepositing process were investigated. Electrocatalytic behaviors of hydrogen evolution reaction on the obtained electrode was studied by steady-state polarization and AC impedance techniques in NaOH solution. The apparent activation energy of hydrogen evolution reaction and stability of the electrode were also reported. The reason of the improvement of the hydrogen evolution was discussed.2. Nickel-Cobalt-Phosphorus, Nickel- Tungsten- Phosphorus and Nickel-Cobalt-Tungsten- Phosphorus alloys were prepared by electroless on ferrous basic body. The result showed that electroless deposition Nickel-Cobalt- Tungsten-Phosphorus is amorphous and has good corrosion resistance Electrocatalytic behaviors of hydrogen evolution reaction on the obtained electrode was studiedby steady-state polarization and in 7mol/L NaOH. Hydrogen evolution potential on the cathode of the electrodes moved positively compared with ferrous cathodes with that of Nickel-Cobalt- Tungsten- Phosphorus moved over 230mV. The morphology element composition and crystal structure were evaluated by SEM and XRD analyses. Nickel-Cobalt- Tungsten- Phosphorus alloy was proved with high catalytic activity which can reduce bath voltage and energy loss during electrolysis .3. Composite electrode Ni-W-TiC>2 was prepared by electrodeposition. Electrocatalytic behaviors of hydrogen evolution reaction on the obtained electrode was studied by steady-state polarization and AC impedance techniques in 7mol/L KOH solution. The apparent activation energy of hydrogen evolution reaction and stability of the electrode were also reported .Experiment results showed that the introduction of TiC>2 to the Ni-W layer lead to an improvement of Electrocatalytic and stability of the layer. The improvement is due to the increase of the surface area and the decrease of the apparent activation energy and change s the hydrogen evolution mechanism.