Synthesis And Electro-catalysis Properties Research Of Metal Phosphide

Hydrogen, a kind of sustainable and pollution-free new energy, has large reserves, renewable and large heat straight advantages. At present, the main way to obtain hydrogen is liquefied of petroleum gas, but electrolysis of water is the most ideal way to get hydrogen, thus the electrode is required to the HER. our work is looking for metal phosphide electrode materials with high performance.In this thesis, we adopt the metal salts as precursor directly, different morphology metal phosphide were required such as CoP nanotubes, CoP nanoball, CoP/Co₂P nanometer chain and Ni₂P nanowires. The synthesis method is the two-step, first of all required the certain morphology of precursor, and then phosphated. This synthetic method is simple, no organic solvent, low reaction temperature etc. And all of the catalysts showed the excellent performance in the HER test.1. CoCCO₃)_0.35Cl_0.2（COH）_1.10 nanorods were synthesised by using a simple hydrothermal, then phosphated by NaH₂PO₂. CoP nanotubes, nanorods, nanoparticals were acquired, and XRD, TEM, SEM, EDS, XPS, were used to prove the crystalline phase and morphology. Formation of the CoP nanotubes is the kirkendall effect by the characterization. CoP nanotubes shows Tafel of 42 mV·dec^-1 and the overpotential of 101 mV with the current density of 10 mA·cm^-2.2. Co nanochains were phosphated in the tube furnace, then the CoP/Co₂P were acquired, then XRD, TEM, SEM, EDS, XPS were used to prove the crystalline phase and morphology. We study the temperature on the crystal of formation product and the influence of the relative activity of HER. The CoP/Co₂P which was synthesised at 400 ℃ shows tafel of 56.3 mV·dec^-1 , and overpotential of 152 mV with the current density of 10 mA·cm^-2.3. the flower-like spherical Co（CO₃）_0.5（OH）_0.11H₂O were synthesized by hydrothermal method, and the morphology does not change through low-temperature phosphidation reaction. XRD, TEM, SEM, were used to prove the crystalline phase and morphology. And it shows tafel of 69.3 mV·dec^-1 , and overpotential of 105 mV with the current density of 10 mA·cm^-2.4. Nickel oxalate was synthesised by simple solvothermal method, and then phosphated in the tube furnace, the product was collect, XRD, TEM, SEM were used to prove the crystalline phase and morphology. The Ni₂P nanowires shows tafel of 83.4 mV·dec^-1 , and overpotential of 216 mV with the current density of 10 mA·cm^-2.