| Nickel hydroxide and nickel-cobalt metal hydroxide materials were well applied in batteries, capacitors and electrochemical catalytic. As we all know, the properties of the material are related to its morphology and composition. By regulation of synthesis conditions and the addition of different components of nickel and cobalt double metal salt precursor may change the morphology, size and structure of materials, thus change the catalytic activity of the materials. In this article, the most important part is changing the value of pH through the process of the synthetic of Ni(OH)2 and Ni1-xCox(OH)2 nano-materials, and investigate the influence of chemical, physical properties and catalytic properties of the materials.In the first part of this paper, Ni(OH)2 was prepared by polyol reduction process with polyvinylpyrrolidone act as a surfactant. Based on the physicochemical characteristic of XRD patterns, TEM and SEM images, FT-IR spectra, we have proposed a possible mechanism for the formation of Ni(OH)2 at different pH. In acid solution, PVP act as an important role for self-assembly to form flower nanostructure; In alkaline solution, due to the high hydrolysis rate, the formation of the primary flakesis fast and the surfactant effect was weakened.The second part is the synthesis of Ni1-xCox(OH)2 with different compose of Co with pH 6.0 and 7.3, respectively. With the result of the characteristics, the ratio of nickel and cobalt is various by the different sedimentation rate; and it may change the morphology and the structure of the materials by adding different components of Co.The eletrocatalysis reaction is called oxygen evolution reaction. For α-Ni(OH)2, the nonmaterial with alkaline system shows the best catalytic performance, seemLy because of the most percentage of NiOOH/Ni(OH)2 and specific surface area. As for Ni1-xCox(OH)2, Nio.8Coo.2(OH)2 with pH 6.0 and Ni0.2Co0.8(OH)2 with pH 7.3 shows the best catalytic performance among others, respectively. Therefore, the catalytic activity may changed by adding components of Co. Associated with the analysis of the physicochemical characterization before, we find that the difference of active side of Ni-Co influenced the performance of catalytic. And in a word, there are a variety of factors for the activity of electric catalytic, such as the morphology, the specific surface area, different content of element and the component of activities. |
