混合价态氧化钨量子点的可控制备及高效调控荧光开关应用研究

The fluorescent-tunable inorganic nanocomposites based on inorganic nanomaterials have been actively attracted in many areas, such as biosensors, information storage, displays. However, Poor construction repeatability and a slow response have limited the application of the fluorescent-tunable inorganic nanocomposites. In this project, it is planed to synthesize the mixed valence tungsten-oxides quantum dots with controllable morphologies,suitable chemical oxidation state and preferential crystal growth direction via a facile low-temperature solvothermal process for the applications of electrochromic technology, and fabricate the fluorescent-tunable inorganic nanocomposites exhibit a quick response, high on/off contrast, remarkable stability and good cycling performance. By optimizing experimental conditions, it is expected to obtain effective electrochromic property. On the merits of selective tungsten oxide quantum dots with large surface-to-volume ratio and small size, the charge-transport and electron-transfer kinetics s could be improved obviously Meanwhile, the pronounced absorptive ability of nanomaterial originating from the enhanced polaron hopping effects may be achieved by tuning the chemical oxidation state of tungsten ions and growth orientation of crystals. The theme of this project mainly covers the efforts on synthetic method, research on to fabricate the fluorescent-tunable inorganic nanocomposites by tungsten oxide quantum dots and inorganic fluorescent quantum dots. Theoretically, this project focuses on investigating the undiscovered relationship of the particle morphology,crystal size and growth direction with the properties of electrochromism, as well as inpecting the intrinsic mechanism of the fluorescent-tunable inorganic nanocomposites and the polyelectrolyte.

纯无机纳米荧光开关材料因其组成具有更优异的稳定性，在生物传感、信息传递、显示器件等都具有极高的应用价值。针对纯无机纳米荧光开关材料在结构构筑重复性差及响应速度较慢的现状，本项目拟采用溶剂热等方法，从控制材料微观结构、化学价态组成、晶体取向等方面入手，通过优化实验条件，合成具有高效电致变色性能的混合价态氧化钨量子点(WO3-x)，并与无机荧光量子点复合应用于电控荧光开关调控。利用量子点小尺寸及表面效应提高电子传输速率。同时通过控制钨的价态和晶体取向来提高声子极化效应，进而提高电控荧光开关性能。本项目研究重点涵盖混合价态氧化钨量子点可控合成，建立混合价态氧化钨量子点/无机荧光量子点电控荧光开关体系。在理论上，本项目立足于探求量子点结晶形貌、生长方向、化学价态与电致变色及荧光开关性能的依赖关系，考察聚电解质性质与混合价态氧化钨量子点/无机荧光量子点电控荧光开关体系性能的内在关系。

电致变色材料及电控荧光开关材料在信息存储、光学显示器件、生物传感等领域具有极大的应用价值，但其应用仍受限于稳定性，响应速度、开关比等问题。本项目通过合理设计，采用溶剂热法实现了混合价态氧化钨纳米材料的可控合成，揭示了混合价态氧化钨纳米材料的构效关系，获得了具有高性能的混合价态氧化钨纳米材料，同时构筑了混合价态氧化钨纳米材料/无机荧光量子点电控荧光开关体系，通过对其调控研究，实现了高性能电致变色材料及电控荧光开关材料的研发。本项目主要取得如下重要进展：（1）基于溶剂种类不同，实现了WO3-x纳米材料氧空位含量的可控调节，揭示了WO3-x纳米材料的氧缺位含量与近红外吸收性能及隔热性能内在规律，具有合适的氧缺位含量的具WO3-x纳米材料有极好的近红外吸收性能及合适的可见光透过率；（2）探究了浓硝酸用量对氮掺杂WO3/W18O49分层纳米材料制备的影响规律，阐明了浓硝酸调控氮掺杂WO3/W18O49纳米材料的形貌，晶体结构及氮含量的内在机制，研究了WO3/W18O49纳米材料的结构与电致变色性能的内在联系，展示了具有优异电致变色性能的WO3/W18O49纳米材料的结构特征。（3）改变不同的表面稳定剂，通过探究表面稳定剂对CdTe量子点的调控机制，制备出高荧光性能的CdTe量子点；（4）构筑出了氮掺杂WO3/W18O49纳米材料/CdTe量子点的电控荧光开关体系，分析了其内在影响因素，阐明了其内在机制，获得了性能优异的电控荧光开关体系。