铜基硫属化物超薄纳米片的液相可控制备及其新奇的近红外光电性质研究与应用

In view of their importance in fundamental research and in real application, copper chalcogenide ultrathin nanosheets (i.e., Cu2-xA UTNSs, A=S, Se, Te) are chosen as the research theme of this project. Particularly, this project is aimed to solve the difficulties existing in the synthesis, characterization and application of such special 2D nanomaterials with emphasis on their fascinating localized surface plasmon resonance (LSPR) properties. To reach such goals, we plan to develop and optimize a lamellar soft template-based synthetic protocol for preparing Cu2-xA UTNSs and for controlling their qualities as well. We also plan to disclose the underlying growth and modulation mechanism of those nanosheets by answering the key question regarding “measurement and tuning of the fine structures of the soft templates”. Moreover, we still plan to fully elucidate the fundamental physics behind the LSPR phenomena associated with semiconductor nanomaterials and to acquire the ability to fine tune such properties, by solving the key question regarding “ measurement and tuning of the carrier properties belonging to Cu2-xA nanosheets at single particle level under resonant excitation. Considering their remarkable near-infrared (NIR) absorption properties, we also plan to design Cu2-xA nanosheet-based NIR photodetectors and catalysts for photoelectrochemical water oxidation (OER), by fully utilizing their strong near-field enhancement effects. This project is thus of particular importance in controlled synthesis of high-quality ultrathin 2D nanostructures of non-layered compounds, and in well-understanding of the LSPR phenomena affiliated to semiconductor nanomaterials, as well as in fabricating high-performance optoelectronic devices based on 2D nanostructures. The main novelty of this project lies in we are able to map and tune the carrier properties belonging to Cu2-x A nanosheets at single particle level under resonant excitation, by using a new home-made micro-optoelectronic testing platform.

鉴于其重要的研究和应用价值，本项目选取铜基硫属化合物（Cu2-xA）超薄纳米片为研究对象，解决其液相制备、局域表面等离子体共振（LSPR）性质研究与应用中面临的难题。为此，拟以创建并优化“片层软模板导向制备工艺”为着力点实现超薄纳米片的可控合成与品质控制；以破解“片层软模板精细结构测控”为切入点揭示纳米片液相生长与调控机制；以解决“单粒子尺度测控共振激发态纳米片载流子特性”为突破口实现对Cu2-xA纳米片LSPR性质的本源剖析与精细调控。借力于其突出的LSPR近场增强效应，设计Cu2-xA纳米片基新型红外光电探测器和水氧化光电催化剂，以获得优异的响应/催化性能。因此本项目无论是对发展非层状化合物超薄二维纳米结构的制备技术，还是对完善半导体LSPR理论，以至对构建二维纳米材料基高效光电器件都具有重要意义。本项目的特色在于构建显微光电测试平台实现单粒子尺度测控Cu2-xA纳米片的LSPR性质。

铜基硫属化合物（Cu2-xA）超薄纳米片因具有良好的溶液可加工性、显著的界面效应以及独特的红外区局域表面等离激元（LSPR）共振吸收特性，是研究LSPR构效关系与界面效应的理想模型材料，也是开展LSPR介导的光电催化、光电器件、太阳能转换研究的理想光功能材料。鉴于其重要的研究和应用价值，本项目选取Cu2-xA超薄纳米片为研究对象，致力于解决其在液相制备、LSPR性质研究与应用中面临的难题。为此，通过发展软模板介导的两步溶剂热合成路线（即将模板“定制”构筑和内嵌纳米晶限域生长分步实施），建立了超薄纳米片的普适性合成工艺并合成出高质量的Cu2-xA超薄纳米片。联合利用多种表征技术监测并剖析了软模板形成、解离、精细结构以及内嵌纳米晶限域生长等关键过程，初步揭示了纳米片液相生长和调控机制。通过系统研究尺寸、组成以及表面修饰对Cu2-xA纳米片聚集体LSPR性质的影响，结合基于近场光学显微技术获取的“单粒子”表征结果，实现了对其LSPR性质的本源剖析和构效关系揭示。开展了Cu2-xA纳米片的光热转换、光电催化、红外探测研究，创制出具有LSPR近场增强效应的新型高性能红外光探测器和高效水分解光/电催化剂。本项目的创新之处在于：1）通过偶联Ag2S粒子，首次获得LSPR吸收强度和光稳定性俱佳的Cu2-xA基等离子体材料，为该类材料的光/电应用扫除关键障碍；2）发现Cu2-xA纳米晶具有光照加速电分解水的新奇性质，首次证实其LSPR热空穴可直接参与氧析出反应，为空穴型等离激元材料的光电应用提供了新启示；3）将Cu2-xA纳米晶与Ag2Se量子点复合，构筑了LSPR增强型高性能自供能红外光探测器，为LSPR介导的红外光电器件的开发提供了新的材料选择。本项目无论是对发展超薄二维纳米结构的制备技术，还是对完善半导体LSPR理论，以至对构建基于LSPR介导的高效光电器件/光电催化剂均具有重要意义。