微区升温电化学SERS新技术及其在核壳纳米粒子上有机小分子电催化体系的应用研究

本项目旨在建立一种可在不同温度下研究有机小分子电催化反应机理的电化学表面增强拉曼光谱（EC-SERS）新技术。该技术利用高频交流电升温技术对负载在热电偶微电极上的核壳纳米粒子进行升温、控温。这一新技术不仅可以在高温下从分子水平实时检测反应中间物种和产物，深入理解电催化反应机理；而且可以通过改变核壳纳米粒子的组成来研究影响纳米粒子的电催化活性的各种因素，从而设计出能在高温下稳定工作的高效电催化剂。利用微区升温技术取代整体升温，可显著提高升温效率且避免对拉曼光路的影响，法拉第电流的减小将有效避免溶液欧姆降所导致的电极电位偏差。此外，通过制备升温微电极阵列并利用拉曼快速成像技术可实现表面多位点同时成像从而获得高通量的信息。预期成果是解决微区升温EC-SERS技术在应用、理论和技术上的难题，提出切实可行的研究方案和技术路线。

The aim of this project is to establish a new method of Electrochemical Surface Enhanced Raman Spectroscopy (EC-SERS) for the study of the mechanism of electrocatalytic reaction of small organic molecules at a variable temperature. The method uses high frequency alternating current heating technology to heat up and control the temperature of core - shell nanoparticles loaded on the thermocouple microelectrodes. The core-shell nanoparticles were using SERS active metal as cores and transition metal as shells. This method can not only detect the reaction species or product on the electrocatalyst in-situ and at a molecular level, thoroughly study the electrocatalytic reaction mechanism; but also can adjust the composition of core-shell nanoparticles to study the various factors that influence the catalytic activity of nanoparticles. The understanding of its mechanism can help to design a highly efficient and stable electrocatalyst working under high temperature. The local heating technology of microelectrode instead of the whole heating method can significantly improve the heating efficiency. Meanwhile, the decrease of Faraday current can also effectively avoid the potential deviation caused by ohmic drop of the solution and the local heating can prevent the heat influence on the light path of Raman spectroscopy. Furthermore, by preparing the heating microelectrode array and using the Raman fast imaging technique, the surface multipoint simultaneous imaging can be achieved to obtain high throughput information. Expected results include the solution of related theoretical and technical problems about the applications of EC-SERS at a variable temperature, and the realization of practical research plan and technical route.