具有等离子共振效应的纳米金属在光解水中的应用

Application of metal nanoparticles with surface plasmon resonance in water splitting

简述光催化分解水反应的基本原理、肖特基结和等离子体共振的概念、等离子体共振在光解水过程的工作机制。介绍Au和Ag等贵金属复合半导体、单一银系化合物、非贵金属等离子体光催化剂。提出具有等离子共振效应的金属纳米颗粒能提高光解水性能的原因是形成肖特基结和具有独特的局域表面等离子共振效应;相比半导体,金属的功函数较大,形成的肖特基结可实现电荷定向迁移;局域表面等离子共振效应通过共振能量转移、增强局部场强和热电子注入等方式拓宽光谱吸收,提高电荷分离效率和光催化效率。认为等离子光催化的研究目前主要集中在Au、Ag等贵金属,其原理有待深入探究,且应理论与实验相结合;开发非贵金属替代物将更有利于降低成本。

The principle of photocatalytic water splitting,the concept of Schottky junction and surface plasmon resonance,and the working mechanisms of plasmonic metal over water splitting were described. The research progress of Au and Ag based semiconductor photocatalysts,series of silver compounds and non-noble metal based semiconductor photocatlysts were systematically introduced. The improved photocatalytic performance for the metal nanoparticles can be attributed to the following two issues. First,the work function of metal is larger than that of semiconductor,and the formation of Schottky junction can realize the spatial transfer of photo-excited-charge carriers. Second,the local surface plasmon resonance effect can expand the spectral absorption,enhance the charge separation efficiency by means of plasmon induced resonance energy transfer,enlarged local electromagnetic field,and the energetic hot electrons injection mechanism,and so on. Although much progress has been reported,plasmonic photocatalysis is still in an early stage. There are still some unsolved problems in this field. It mainly focuses on the precious metals Au and Ag and so forth. Their working principle needs to be further studied. The combination of theory and experiment,the development of cheap non-precious metal substitutes are of the urgent expectation.