| In order to solve the increasingly serious problems of energy and environment, hydrogen is considered to be one of important candidate who solve these problems. At the same time, the main method of generating hydrogen energy is electrolysis of water. We all know that complex nanomaterials have good electrocatalytic properties. In order to improve the electrocatalytic properties of nanomaterials, it is an effective way to control the morphology, and it is to improve their electrocatalytic properties by increasing their surface area.In the first part of this paper, we synthesized the PdxNi100-x bimetallic nanopartics in the system of benzyl alcohol, and benzoic acid as surfactant and polyvinyl pyrrolidone (PVP) asstabilizer. We analyzed the structure of PdxNi100-x nanoparticles by these characterizations of XRD, TEM, XPS, EDX elemental line scanning, EDX elemental mapping and so on. After the PdxNi100-x nanoparticles were loaded on carbon nanotubes, and PdxNi100-x/C nanomaterials were obtained, the HER electrocatalytic properties of them were evaluated. Then the loaded PdxNi100-x/C nanomaterials were phosphated at high temperature, and a new kind of complex nanomaterial Pdx-Ni2P/C was obtained. We explore the effects of phosphated time, phosphated temperature and the ratio of nickel to phosphorus, and proposed the formation mechanism of Pdx-Ni2P/C complex nanomaterial by XRD, TEM, XPS, EDX elemental line scanning, EDX elemental mapping and so on. And we analyzed the structure of Pdx-Ni2P/C complex nanomaterial. At the same time, the HER electrocatalytic properties of Pdx-Ni2P/C complex nanomaterials were evaluated, HER electrocatalytic tests show that the HER electrocatalytic property of Pd2o-Ni2P/C complex nanomaterial is best. When the current density j=-10 mA-cm'2, the overpotential of Pd2o-Ni2P/C complex nanomaterials is-132.7 mV (vs.RHE). Tafel slope is 93 mV/dec and TOF is 5.1 S-1 (v=-200 mV).In the second part of this paper, we synthesized thecertain morphology NixFe3-xO4 complex nanomaterials in system of ethylene glycol by solvothermal method, and urea as reducing agent and cetyl trimethyl ammonium bromide (CTAB) as surfactant. The ratios of Nickel to Tron of NixFe3-xO4 complex nanomaterials were determined by these characterizations of XRD, TEM, EDX and magnetic testing and so on. Then the OER electrocatalytic properties of NixFe3-xO4 complex nanomaterials were evaluated. OER electrocatalytic tests show that the OER electrocatalytic property of Ni2Fe04 complex nanomaterial is best. The initial overpotential of Ni2Fe04 complex nanomaterial is 0.58 V (vs.Ag/AgCl) and Tafel slope is 76 mV/dec.Based on the electrochemical characterizations of the complex nanomaterials, the HER electrocatalytic properties of complex nanomaterials are gradually increased with the gradual increase of Pd in the first part. After phosphated, the HER electrocatalytic properties of Pdx-Ni2P/C complex nanomaterials are better than PdxNi100-x/C nanomaterials. The OER electrocatalytic properties of NixFe3-xO4 complex nanomaterials are gradually increased with the gradual increase of Ni in the second part. So the electrochemical characterizations of the complex nanomaterials are not only affected by the proportion of elements, but also are related by these factors of morphology and specific surface area of complex nanomaterials. |
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