II-VI族一维半导体纳米异质结与贵金属纳米颗粒的复合及性质研究

Photoinduced charge separation and transfer occurred in noble-semiconductor nanoheterostructures due to Plasmonic effect. The heterostructure therefore revealed important applications in photovolved, photocatalysis, and hydrogen energy fields. Such study have been become a hot research topic in recent years. According to the development of study, the heterostructures have been fabricated through the growth of noble nanoparticles (NPs) on semiconductor nanoheterostructures in this project. The synthesis kinetics of the heterostructures and the separation and transfer of photogenerated carriers in the heterostructures are studied. The project includes (1) the synthesis of 1D nanorods and nanoheterostructures of CdSe, CdTe, and CdS: to prepare 1D heterostructures with one or multi components and to probe the relationship of structure, phase, photoluminescence (PL), and other properties. (2) The deposition and growth of Au/Ag/Pt NPs on the semiconductor nanoheterostructures: to control the position, amount, structure, and morphology of the noble NPs. By using capping agents and controlling the growth process, the morphology and structure of the nanoheterostructures were precisely adjusted. The formation kinetics and property evolution including absorption and PL spectra, fluorescence lifetime, and luminescence characteristics of single particle of the nanoheterostructures etc. have been studied with the variation of their composition and preparation conditions. The charge separation and transfer within the nanoheterostructure was discussed. The investigations of photocatalysis, water splitting, and others of the nanoheterostructure were carried out for the purpose of finding a material for important applications in energy materials, solar cell, and lithium battery.

贵金属的等离子体共振效应会引起半导体纳米异质结中光生载流子的分离和转移，两者复合形成的一维纳米材料在合成化学、能带分析、新材料探索等领域备受关注，这些一维纳米异质材料在光伏、光催化、新能源等领域有重要的应用。本项目针对本领域的研究需求，以一维半导体纳米异质结为基础，研究贵金属在半导体异质结上的沉积过程，探索合成动力学及光生载流子的分离与复合。其主要内容包括（1）CdSe、CdTe、CdS一维纳米棒及异质结的合成：合成两组分及三组分一维异质结，研究其结构、相组成和发光等性质；（2）Au/Ag/Pt等贵金属纳米晶在异质结上的生长：有效控制其生长的位置、结构、形貌及数量。通过结构控制及盖帽剂的使用研究贵金属的选择性生长，精细控制多组分一维纳米异质结的形貌与组成，研究复合结构的形成动力学及性质（吸收、单颗粒荧光、荧光寿命等）演变，分析电荷分离及迁移过程，并用于光催化、太阳能电池、锂电等领域。

依据开始的研究计划，本项目针对本领域的研究需求，以一维半导体纳米异质结为基础，研究贵金属在半导体异质结上的沉积过程，探索合成动力学及光生载流子的分离与复合。其主要内容包括（1）CdSe、CdTe、CdS一维纳米棒及异质结的合成：合成两组分及三组分一维异质结，研究其结构、相组成和发光等性质；（2）Au/Ag/Pt等贵金属纳米晶在异质结上的生长：有效控制其生长的位置、结构、形貌及数量。通过结构控制及盖帽剂的使用研究贵金属的选择性生长，精细控制多组分一维纳米异质结的形貌与组成，研究复合结构的形成动力学及性质（吸收、单颗粒荧光、荧光寿命等）演变，分析电荷分离及迁移过程，并用于光催化、太阳能电池、锂电等领域。主要研究成果集中在两方面，首先是半导体纳米晶的控制合成，得到不同形貌的半导体纳米材料，在这些材料上生长贵金属异质结；另一方面是合成不同形貌、不同组成的贵金属纳米颗粒，例如合成球形、棒状、三角形等金银纳米晶，在此基础上生长半导体异质结，例如可以控制半导体材料生长在不同的位置，解决了异相可控生长的难题，不仅获得了理论成果，发表几十篇SCI收录论文，也开发了一系列有应用前景的材料，特别是利用两者之间特殊的光学性质，为将来的应用奠定基础。