Synthesis Of Novel Electrocatalyst And Their Electrocatalytic Properties For Water Splitting

Hydrogen energy, as the most promising and cleanest energy in the 21 st century, has attracted strongly attention due to increasing energy demands and growing global environmental concerns associated with excessive fossil fuels usage. As a clean route to produce H2, the electrochemical water splitting in alkaline solution has naturally invested tremendously research. In this paper, transition metal oxides or hydroxides,including Co Fe-LDH, Co3O4@Ni, Ni Mo O4@Ni, have been obtained by using simple methods and investigated as electrocatalyst toward water splitting. The physical properties of as-prepared materials were investigated by X-ray diffraction(XRD)patterns, scanning electron microscopy(SEM), high-resolution transmission electron microscope(HRTEM), X-ray photoelectron spectroscopy(XPS), N2absorption-desorption. The electrochemical activity was evaluated by linear sweep voltammetry, chronoamperometry and electrochemical impedance spectroscopy in alkaline solution. In this paper, the research contents were as follows:1. Mesoporous flake-like Co Fe-LDH catalyst was prepared by reflux method at low-temperature. All of results showed that Co Fe-LDH catalyst possessed better catalytic performance and more excellent stability toward oxygen evolution reaction when the molar ratio of metal ions reaches 4:1(Co/Fe=4).2. The three-dimensional Co3O4 was directly grown on Ni foam via a simple hydrothermal method, named as Co3O4@Ni. The morphologies and nanostructure of Co3O4@Ni was investigated by SEM, which revealed that Co3O4 dense films were uniformly decorated on the surface of Ni foam. Simultaneously, the electrochemical performance tests demonstrated the Co3O4@Ni catalyst exhibit excellent properties of hydrogen evolution reaction and oxygen evolution reaction. Compared with the Co3O4 nanoparticles, the higher catalytic activity of Co3O4@Ni may be attributed to the high conductivity of Ni foam substrate, mesoporous structure and unique morphology.3. High-performance Ni Mo O4 directly grown on Ni foam was prepared by the hydrothermal method. By using solvent to control its morphology, hierarchicalNi Mo O4 nanosphere arrays were formed. Electrochemical results showed that Ni Mo O4 catalyst has the outstanding performance toward electrochemical water splitting. The good catalytic activity of Ni Mo O4 was comparable to many excellent reported catalysts.