Electrocatalytic decomposition of water to hydrogen is an important way to reduce environmental pollution and achieve renewable clean energy. The development of efficient and stable catalysts for hydrogen production has important scientific value and practical significance. Graphene materials because of its large surface area, good conductivity , The advantages of stability, etc., are widely used in the electrocatalytic decomposition of water to hydrogen production. However, graphene materials have only been used as a carrier for catalysts so far, and the hydrogen evolution ability has been improved through the use of cocatalyst loading or heteroatom doping. Graphene itself as a catalyst to achieve the electrocatalytic hydrogen evolution of the relevant reports are relatively missing.
Researchers at the Key Laboratory of Organic Solids Institute of the Institute of Chemistry, Chinese Academy of Sciences have long been dedicated to chemical vapor deposition and etching of graphene, and have prepared a variety of graphenes with different layers, structures, dimensions and morphologies. Materials, effective control of the various properties of graphene. Recently, the research group and the Key Laboratory of Photochemical Conversion and Functional Materials, Institute of Physics and Chemistry, Chinese Academy of Sciences, Wu Xiaozhu Group, Associate Professor, State Key Laboratory of Tribology, Department of Mechanical Engineering, Tsinghua University Tianbao cooperated to directly prepare three-dimensional graphene materials without metal catalyst and without template, and further regulated the morphology of graphene.
The three-dimensional graphene obtained in this study consists of a high-density upright graphene-coated silica nanowire network, in which the silicon oxide nanowire network is prepared in situ on a silicon substrate by chemical vapor deposition. High-density boundary sites in two-dimensional planar graphene and three-dimensional graphene materials can be used as active centers to catalyze the adsorption and reduction of hydrogen by protons. This is the first time in the world that the graphene material is controlled by its morphology, and its non-doping is realized. Heterogeneous, high-performance electrocatalytic decomposition of water in the absence of co-catalysts is used to decompose hydrogen evolution. Electrochemical measurements show that the initial voltage for the electrochemical evolution of three-dimensional graphene materials with morphology optimization is only ~18 mV, which is very close to commercial Pt/C. Theoretical studies have demonstrated that excellent hydrogen evolution energy sources are available at the tip sites of three-dimensional graphene materials. These high-density boundary tip sites achieve a shift from catalytically inert intrinsic graphene to high catalytic performance. The study was graphene. The application of materials in the field of hydrogen evolution in electrolyzed water provides a theoretical and practical basis.
The relevant research results were published in Angew. Chem. Int. Ed.. The study was funded by the National Natural Science Foundation of China, the Ministry of Science and Technology, and the Chinese Academy of Sciences.
Figure 1. Three-dimensional graphene network with high density boundary sites
Figure 2. Electrocatalytic decomposition of three-dimensional graphene network materials
