超细碳化物纳米晶的可控合成及性能研究

Carbide nanocrystals have many unique properties, such as high chemical stability and biocompatibility, different from conventional nanocrystals. However, controllable fabrication of carbide nanocrystals is still a great challenge. Our aim is to develop a new method that can controllably fabricate ultrafine carbide nanocrystals with sizes < 10 nm, and study their optoelectronic properties and explore their applications in bioimaging, optoelectronic devices and catalysis. Using organic liquids as carbon precursors, carbide reactions are intentionally introduced into the extremely high temperature and high pressure conditions induced by laser ablation to generate carbide nanocrystals. The nanosecond duration of the laser pulses determines the millisecond growth time of the carbide nanocrystals, beneficial to prepare ultrafine nanocrystals. Through adopting organic liquids with different capabilities to supply carbon atoms and adjusting the laser parameters, we can achieve controllable fabrication of carbide nanocrystals, even yield carbide nanocrystals with complex structures, such as hollow, ring, and core-shell structures. Controllable doping will also be investigated as another tool to manipulate the properties of the carbide nanocrystals. The relationship between the structure of the carbide nanocrystals and their optoelectronic properties will be built based on first principle studies in conjunction with experimental results. The relationship will enable us to rationally design carbide nanocrystals oriented for applications in bioimaging, optoelectronic devices and catalytic fields.

碳化物纳米晶具有不同于常规纳米晶的诸多优点，特别是化学惰性和生物兼容性；然而，碳化物超细纳米晶的可控合成仍然是一个重大难题。本项目的核心内容是开发可控制备 < 10 nm超细碳化物纳米晶的方法、研究其光电特性及在生物医学成像、光电器件和催化等领域的应用。合成方法是通过利用有机溶剂作为碳源，在激光烧蚀产生的超高温、超高压的极端环境下引入可控的碳化反应，制备碳化物纳米晶。纳米级别的激光脉冲宽度决定纳米晶的生长时间在毫秒水平，是制备碳化物超细纳米晶最理想的方法。通过选择具有不同供给碳能力的溶剂和不同波长、脉冲宽度的激光实现对纳米晶结构控制，达到可控合成的目标，甚至有望获得复杂结构（如空心、圆环、核壳等）纳米晶。探索对超细纳米晶的可控掺杂，为性能的调控提供一个新的强有力工具。通过第一性原理模拟结合实验验证，建立纳米晶结构与光电性能的关联，实现面向生物医学成像、光电器件和催化等领域的应用的按需构筑。

碳化物等纳米晶在诸多领域具有广泛的应用前景。在本项目的支持下，着重研究了采用激光辅助液相合成纳米晶的方法、所合成的纳米晶光学特性及作为润滑油添加剂和在光电、传感等领域的应用前景。重要的科研成果和关键数据包括：1）采用激光辐照液体中的无规则形状颗粒，能够大批量制备球形亚微米颗粒，该技术有望发展成为球形亚微米颗粒的宏量制备技术。初步探索了硫化钼 球形亚微米颗粒作为润滑油添加剂的应用，大幅提高了润滑液的品质。2）发展了室温制备羧卤铅矿包裹钙钛矿纳米晶的技术，能够获得具有特定形状的微米发光颗粒，颗粒的整体和局部发光性能能够准备控制，在光电显示等领域具有潜在应用前景。3）通过液相合成的金属有机框架包裹金颗粒作为表面增强拉曼散射衬底，制备了具有高灵敏性和强定量检测的传感器件，在痕量检测领域具有重要应用。围绕上述研究内容，项目负责人作为（共同）通讯作者在SCI期刊上共发表论文12篇，其中影响因子(IF)大于10的有5篇，JCR一区论文有10篇，具体包括Nano Letters (2020，20, 2316；IF 11.24;一区)，Nano Letters (2020，20, 7304)，Green Chemistry (2020，22，3608；IF 9.48；一区)，Advanced Science (2020，7,1903143；IF15.84；一区)， Science Advances (2019, 5, eaax0380; IF 13.12；一区)，Journal of Physical Chemistry Letters (2019, 10, 6484;IF 6.71;一区)，Advanced Materials (2018,1805686;IF 27.4;一区)， Journal of Materials Chemistry C (2018, 6, 12484;IF 7.06；一区)， ACS Applied Materials & Interfaces (2018, 10, 40180;IF 8.76;一区)，ACS Sensors (2018, 3, 2343; IF 7.33; 一区)，Nanotechnology (2018, 29, 414001/265704;IF 3.55；二区)。该项目为纳米晶的液相合成及应用的后续研究奠定了基础。