表面等离子体共振效应驱动的高选择性光电催化及其机理研究

Photoelectrocatalysis is considered as one of the most promising technologies to solve the problems of energy shortage and environmental pollution but its development is restricted by the poor selectivity of traditional photoelectrocatalysts. Plasmonic nanomaterials show great potential in selective photoelectrocatalysis owing to their unique photoelectric properties. Currently, their application in selectivity improvement is mainly focused on photocatalysis but seldom on photoelectrocatalysis. This project aims to realize highly selective photoelectrocatalysis on plasmonic nanomaterials by virtue of its surface plasmon resonance (SPR) effect and to reveal the reaction mechanism. Specifically, general characteristics of SPR-driven photoelectrochemical reactions will be firstly explored in order to discover a proper way to tune photoelectrocatalysts' selectivity. Then, the influence of different surface modification strategies on the catalytic performance will be studied and a general method to build highly active and selective nanocatalysts is expected to be established based on SPR effect. Finally, electron transfer and energy transmission processes in photoelectrocatalytic reactions will be studied by SERS and fluorescence imaging, and the mechanism of SPR-driven high selectivity will be proposed. This work will probably pave the way for the rational design of novel photoelectrocatalysts with high light conversion rate, excellent activity and outstanding selectivity.

光电催化是一种最有希望解决能源短缺和环境污染问题的绿色光电转换技术，而催化剂选择性差成为限制其发展的瓶颈。等离子体纳米材料因其新颖独特的光电性质在提高催化选择性中显示出巨大潜力，但其研究主要聚焦于光催化，在光电催化领域尚处于开发阶段。针对光电催化剂选择性差这一关键科学问题，本项目拟利用金属纳米材料的表面等离子体共振（SPR）效应实现探针分子的高选择性可控光电催化并探究相关反应机理。主要包括探索SPR驱动的高选择性光电化学反应的特性，找到光与电协同调控催化剂选择性的条件和规律；研究不同表界面改性条件对纳米材料选择性和活性的影响，建立基于SPR构筑高活性和高选择性光电催化剂的一般方法；借助SERS和荧光成像技术研究光电化学反应中的电子转移和能量传输过程，阐明SPR驱动的高选择性光电催化机理。本项目研究成果将为开发具有自主知识产权的高吸光率、高活性、高选择性纳米光电催化剂体系奠定理论和实验基础。

光电催化是一种最有希望解决能源短缺和环境污染问题的绿色光电转换技术，而催化剂选择性差成为限制其发展的瓶颈。等离子体纳米材料因其新颖独特的光电性质在提高催化选择性中显示出巨大潜力。本项目研发了Au纳米球、Au@Pt纳米球、Au@Pd@Pt纳米棒等一系列Au基等离子体纳米光电催化剂，Au的表面等离子体共振（SPR）效应使得它们在电催化氧化还原反应过程中表现出良好的光响应特性，有效地提高了产氢、二氧化碳转化和硝基苯还原反应的活性和选择性。最重要的是，在研究Au纳米球表面硝基苯电氧化还原反应过程中，我们发现，简单的光辐射就能同时提高SPR介导的催化反应活性和选择性，实现特定分子的高选择性可控光电催化，在光照条件下，Au纳米粒子表面硝基苯到苯羟胺的转化率约提高了14%，而苯羟胺到亚硝基苯的转化率降低了13%。我们还结合原位表面增强拉曼光谱技术和密度泛函理论模拟阐明了SPR驱动的高选择性光电催化反应机理。研究表明，这种特殊的选择性由加速的热电子转移和相应的残余热空穴共同贡献的。此外，结合课题组的研究背景和前期工作基础，我们还开展了水系锌基储能材料及器件相关的探索性研究工作。本项目研究成果为开发具有自主知识产权的高吸光率、高活性、高选择性纳米光电催化剂体系以及水系二次电池奠定了理论和实验基础。