Preparation And Electrocatalytic Water Splitting Properties Of Three Dimensional Self-supported Electrode Materials

Hydrogen, one of the most clean fuels, was expected to play a critical role in the future energy landscape for its high energy density, environmental friendliness, safty. In addition, no greenhouse gases were produced during its consumption except water. These advantages make it an ideal route to convert light/electricity to chemical energy and have attracted worldwide interests. Noble metals（Pt, Ir ect.） based composites show excellent catalytic properties, however, was hindered by their low crustal abundance and high price. Design and synthesize highly efficient water splitting catalysts using non-noble metals becomes the research focus currently.Traditional catalysts are mainly in powdered form and have to be drop-cast onto the glassy carbon electrode under the assisstance of organic binder, which may inturn affect the contact between the catalysts and electrolyte, mass and electron transfer. The use of polymer binder may also block the active reaction sites leading to a reduced catalytic activity. The tedious procedure increases the overall cost and make it unattractive. After all the work electrode was limited by the area of the glassy carbon and restricted its application. Herein, two binder-free materials Mo2C/CC and Cu₂S/CF were newly designed and synthesized and their electrochemical catalystic performance were further investigated. The selfsupported structure could offer abundant reactive sites, facilitate ion transfer and promote its industrial application. The thesis mainly includs the following two parts:（1） Ammonium molybdate and hexadecyl trimethyl ammonium bromide first selfassimblied into supramolecular polymers Mo-CTA/CC on the surface of carbon cloth（CC） as the precusor, a subsequent calcination under Ar protection leading to the in situ formation of Mo2C/CC. CTAB functions as the carbon source and can also fix the Mo7O246- onto the CC surface. Mo2C/CC delivers excellent electrochemical catalytic performance, a current density of 10 m A/cm2 was delivered under an overpotential of 140 m V, it also shows good stability in acid enviroment and gives a Farady efficiency nearly 100%. Its superior performance can be attributed to the unique three demisional structure with enhanced ion conductivity and more reactive sites exposed and the synergetic effect between the substrate and Mo2 C.（2） Cu₂S was first confirmed to be active towards hydrogen evolution reaction and was prepared by a facile hydrother method. In the synthesis, copper foam（CF） and tiourea were employed as the reactants in the presence of Co2+ or Ni2+. We discussed the Cu₂S formation process in detail, systematically investigated the effect of Co2+ concentration, anion species on the morphology and catalytic property of the product. The experimental results show that the as obtained Cu₂S/CF material possesses excellent catalytic ability in neutral media, a current density of 10 m A/cm2 was reached under an overpotential of 190 m V, it also shows good stability in neutral enviroment and gives a Farady efficiency nearly 100%.