常压微等离子体的激光诱导激发增强和基于高激发常压微等离子体辅助电化学反应的纳米制备

Discharge-ignited atmospheric pressure microplasma-assisted electrochemical reactions have been successfully used for liquid-phase nanofabrication, which benefits from the high excitation of the plasmas and the high density of reactive particles in the plasmas. By laser-induced excitation enhancement of discharge-ignited atmospheric pressure microplasmas, i.e. by dual excitation of gas discharge and laser irradiation, this project plans to generate atmospheric pressure microplasmas which have higher excitation than discharge-ignited atmospheric pressure microplasmas. The project will also use the generated highly excited atmospheric pressure microplasmas to assist and promote electrochemical reactions occurring in precursor solutions for the synthesis and preparation of nanoparticles. Through the examination of the plasma characteristics and movement as a whole by means of probe beam deflection and shadow graph and the examination of the space-time behaviors and the microscopic processes of plasma particles using plasma optical emission spectroscopy, and in combination with plasma simulation, we will study the action of laser irradiation on discharge-ignited microplasmas, the time and space evolution of the plasma state and characteristics and their dependence on discharge and laser parameters, aiming at the generation of highly excited atmospheric pressure microplasmas. And through the examination of the features of the interface between the plasma and liquid and the behaviors of particles in the interface, we will study the actions of reactive plasma particles on the liquid beneath the plasma and the assistance and promotion of electrochemical reactions occurring in the solutions by the plasma. We will also demonstrate the synthesis and preparation of some nanomaterials such as carbon, noble metal and compound semiconductor nanoparticles to explore a new method of nanofabrication based on highly excited atmospheric pressure microplasma-assisted electrochemical reactions.

常压放电微等离子体辅助电化学反应已成功应用于液相纳米制备，这一制备技术受惠于等离子体的高激发度和等离子体活性粒子的高密度。本项目拟通过对常压放电微等离子体的激光诱导激发增强，即采用放电和激光双重激励，产生更高激发度的常压微等离子体，并以此辅助和促进溶液中的电化学反应，应用于纳米颗粒的合成制备。以探测光束偏折和阴影照相法考察等离子体的整体特性和运动，用时空分辨的等离子体发射光谱法考察等离子体粒子的时空行为和微观过程，并结合等离子体模拟，研究激光对放电微等离子体的作用，了解等离子体状态和特性的时空演化和随放电和激光参数的演变，进而产生高激发度的常压微等离子体。通过等离子体-液体界面特性和界面粒子行为的考察，研究等离子体活性粒子对液体的作用和对发生在溶液中电化学反应的辅助和促进，并通过碳、贵金属和化合物半导体等若干纳米颗粒的合成制备，摸索基于高激发常压微等离子体辅助电化学反应的纳米制备新方法。

材料科学是低温等离子体的重要应用领域之一，包括等离子体辅助纳米材料制备和处理，而制备和处理的效果和效率与等离子体的激发度和活性密切相关。电激发和光激发是引发等离子体的两种常用手段，包括引发常压微等离子体。本项目采用放电和激光辐照引发高激发度、高化学活性和多组分等离子体，并用以纳米材料制备和处理的应用探索。通过对电极形状的改进以改变常压放电微等离子体的构型，增大了等离子体的体积和反应区域，更通过激光诱导激发或激波辅助激发的方法提高了等离子体的激发度。用光束偏折和时空分辨的等离子体光谱诊断和测量方法结合光谱拟合和温度估算，考察了等离子体演变等的特性和增强激发的效果，并利用光谱测量和分析通过对等离子体气相物质的识别及其变化运动的观察，了解等离子体中微观粒子之间碰撞、激发、电离、解离等过程，探讨了电场对气体的电击穿、激光对气体的光击穿和对微观粒子的光激发等导致等离子体高激发、高活性的机理，优化激发条件。研究了高激发度、高化学活性的等离子体中发生的气相反应和诱发的液相反应，并以此开展纳米材料的制备和处理，制备了金属、合金、非金属、半导体等多种纳米材料，特别是用金属纳米颗粒或半导体纳米薄层修饰的复合纳米材料，改变或增强了材料的某些性质，包括材料光响应的增大和材料光化学活性和光电化学活性的提高。结合材料的形貌观察、结构表征、特性测试以及应用尝试，探讨和了解等离子体状态和特性对材料成分、结构、形貌和性质的影响。在多种纳米材料合成制备的基础上，研究了材料的光学、光电、光化学和光电化学等性质，尤其是纳米颗粒或薄层的修饰对材料特性的优化和材料在光吸收、光发射、光电转换和光催化等方面的应用。项目资助下已发表第一标注的SCIE论文14篇，另有2篇投稿。培养硕士6名，中西部高等学校青年骨干教师国内访问学者1名，另有2名在读博士生预期2022年夏季毕业，1名硕士生转博。