类铂碳化钒与单层石墨烯异质结构的设计制备及电催化氢氧化增强机理的研究

设计制备高效廉价电催化剂替代贵金属一直以来是人们关注的焦点。本研究项目旨在通过类铂材料碳化钒和石墨烯之间存在的晶格匹配，在碳化钒特定晶面上外延生长单层石墨烯，形成两者的异质结构，获得类似铂的电催化氢氧化性能。碳化钒是一种很少有研究者涉及的类铂材料，碳原子掺杂对钒原子d带的影响导致碳化钒的性质向铂靠拢。在碳化钒特定晶面上形成单层石墨烯，对碳化钒特定晶面产生进一步的调控作用，从而优化碳化钒的电催化性能。申请人前期的理论模拟已经揭示，碳化钒和单层石墨烯的异质结构具有接近甚至超越铂的电催化性能。通过构建两者的异质结构，实验验证其卓越的电催化氢氧化性能，同时结合原位电化学表征，研究氢过程中的组份变化、结构演化，提出合理的反应机理。该项目的成功实施不但可以获得电催化氢氧化性能优异的廉价材料，具有替代铂的现实作用，而且可以为后续开发更多的类铂材料提供理论和实践两方面的借鉴，具有十分重要的指导意义。

Designed fabrication of high-efficiency and low-cost electro-catalysts to replace noble metals is always a Hotpoint. This proposal aims at formation of a hetero-structure between platinum-like vanadium carbide and single-layered graphene, and realization of the highly efficient hydrogen oxidation reaction. The formation is based on the low crystal-mismatch strategy and the epitaxial growth happens on the specific crystal plane of vanadium carbide. Vanadium carbide is a scarcely reported platinum-like material and the carbon atoms’ doping would influence the vanadium atoms’ d bands to further result in the platinum-like properties. By coating single-layered graphene on the specific crystal plane of vanadium carbide, the catalytic features of hydrogen evolution reaction will continue to be tailored and optimized. Our previous simulation and modeling has already indicated that the hetero-structure of vanadium carbide and single-layered graphene has a great potential to present outstanding performance on hydrogen oxidation reaction, which is close to or even better than platinum. By construction of the hetero-structure and verification of the actual properties of hydrogen oxidation, the reasonable reaction mechanism will be given, especially under aid of the in-situ electrochemical characterizations to determine the changes of structure and ingredients during hydrogen oxidation. The success of this project can not only achieve the perfect electro-catalysts for hydrogen oxidation to replace platinum, but also provide a very important theoretical and experimental model to exploit more platinum-like materials.