Preparation Of Ni-Mo Alloy And Studies On Its Characterizations Of HER

Hydrogen energy is the ideal energy of 21th century. Electrolyzing water to make hydrogen is the most effective method. And in this research area, most important point is to develop new materials which are active in HER (Hydrogen Evolution Reaction). The study indicated that transition metals could reduce the over potential in HER by cooperating effect. And Ni-Mo alloy is the best one of all binary alloy. Electro-codepositing is a new technique to prepare materials. And the composite coatings has many excellent characters in mechanics, photics, electrics, thermodynamics and magnetics. It has an extensive prospect. As a HER material, the composite particulates can enlarge the surface area and they can cooperate with the alloy to enhance the activity of HER. At present, the study on Ni-Mo compositing coatings is not familiar. So these alloy has a great development space.In this paper, we prepare the Ni-Mo composite electrode by electro-codepositing. Before this we research the prepare condition of Ni-Mo alloy, the HER activity was discovered by steady state polarization curve, the component of coatings was analyzinged by titration with EDTA. The structure and appearance of the coatings was observed by XRD and SEM. The effect of the prepare condition (the concentration of main salt, deposition current density, pH, temperature, time) was obtained. Base these conditions, using hydrogen storage alloy powder(AB₅), Ni powder, CeO₂ powder as composite particulate we get the co-depositings, and we get the coatings which was modified by rare earth salt, and the character was studied by the same way. The results indicate that the species of the powder, depositing time have the key effect on the coatings.It indicates that the optical condition of Ni-Mo alloy preparation is Dk=100 mA/cm²,pH=8～9,T=35℃,and the longer time is better. The coatings which is prepared under this condition has the content of Mo is about 40 %, and the character of HER is better. Under the current density of 0.1 A/cm², the over potential is 500 mV lower than that of Ni electrode. The SEM result shows that the structure of Ni-Mo alloy is porous, and the XRD results shows the coatings is amorphous, and the size is about 1.3 nm.The size of Ni-Mo(RE) is smaller than that of the Ni-Mo alloy. The roughness of the composite coatings becomes more obvious by adding the particulate in the coatings. By these two method we make the over potential of composite coatings is lower than that of Ni-Mo alloy and much lower than Ni. And we found that the longer depositing time, appropriate composite particulates and stirring is good for the coatings activity on HER. The parameters of electro-reaction kinetics and the result of the EIS indicate that the HER on these electrode react as the Volmer-Heyrovsky mechanism.