硫(-II)化合物氧化过程的电化学原位无标记表面增强拉曼光谱检测与调控

Given the difficulties that chemical titration, UV and FTIR spectroscopy, electrochemical analysis, chromatography, etc. have encountered in the simultaneous identification of different sulfur compounds in a sulfur reaction system, this project will employ electrochemical deposition and template substitution techniques to develop controlled-synthesis of silver@noble metals (e.g., Au, Pt, Pd) core-shell nano-dendrites on a conductive silicon substrate for SERS applications.Influences of the particle size, morphology and thickness of the core and shell layer on the SERS measurements of sulfur compounds will be sysmatically examined in this project. Thiosulfate,thiocyanate,thiourea and ethylene thiourea will be investigated as the model sulfur compounds to undergo electrochemical reactions,in which potential and current will be used as the control parameter to manifest the reaction dynamics. Time-resolved in situ SERS technique will be employed to identify and follow the evolution of sulfur intermediates. The proposed experiments are expected to lead to the establishment of a general model for the sulfur(II) compounds reactions, which shall be capable of accounting for complex nonlinear dynamical behaviors such as oscillations and chaos seen in those systems. The case study of the sulfur(II) compounds oxidation process will allow us to understand how to manipulate the reaction and to gain insights into the conversion mechanisms of sulfur pollutants, which will form a solid foundation for developing green chemical processes for the sulfur pollution control. In the long term, this project will have significant impact on the development of time-resolved SERS technology and of nonlinear dynamics control theory in inorganic chemical reactions.

针对化学滴定法、紫外和红外光谱法、电化学分析法、色谱法等对硫化学反应过程中不同价态硫组分识别的困难，本课题拟运用电化学沉积技术和模板取代反应在导电硅基材表面可控生长具有三维核壳结构的银@贵金属（如Au、Pt、Pd等）纳米枝晶以构筑高灵敏原位SERS检测的电极界面,并深入探讨核、壳的类型、尺寸、厚度以及形貌等对硫化物及其氧化中间物表面增强拉曼光谱效应的影响。以硫代硫酸盐、硫氰酸盐、硫脲以及乙烯硫脲等为模型硫化物，通过电位/电流控制反应速率，利用原位SERS技术识别不同硫氧中间体及其动力学演化和相位关系。建立硫（－II）氧化过程的一般动力学模型，实现硫化学反应动力学行为如振荡、混沌的机理模拟与解释。运用模型调控硫（－II）的氧化过程，认识和理解硫化物的转化与控制机制。本项目的研究成果将为进一步发展时间分辨SERS技术和丰富无机化学反应的非线性动力学控制理论提供重要的实验基础。

硫污染的控制是化学化工、环境等领域的前沿研究方向。控制硫污染的核心在于深入理解复杂硫化学反应动力学机理，但如何实现硫氧中间体的原位跟踪识别一直是本领域的难题。为此本项目运用多种方法和技术，可控合成了硫化铅量子点纳米组装棒、葫芦串结构的碲基异质结材料、石墨烯纳米带负载石墨烯量子点杂化材料等多种用于SERS检测的基底材料，并对硫化物及其氧化中间物表面增强拉曼光谱效应进行了深入研究。同时建立了硫代硫酸盐、硫氰酸盐、硫脲以及乙烯硫脲等硫化物的一般动力学模型，初步实现了硫化学反应动力学行为如振荡、混沌的机理模拟与解释。主要工作包括：(1)开创性的发展了一种基于微波加热超声辅助法合成多种结构的硫化铅量子点微米组装棒。运用该材料做SERS检测基底，发现其表面增强拉曼强度跟金纳米棒相当。(2)发展了一种基于微波辅助合成的新技术，一步可控合成了一系列具有新颖糖葫芦结构的碲基异质结多组份材料。发现此种材料虽对拉曼光谱没有很好的表面增强效应，但其实一种很好的太阳能光解水制氢催化材料。(3)开辟了一种卤代烃原位脱卤聚合的新途径，开创性地制备了一种新型的一种石墨烯量子点/石墨烯纳米带杂化材料，该全碳电催化剂，具有目前最高氧还原活性和稳定性。相关研究参加国际会议2人次，国内会5人次，并在J.Am.Chem.Soc.、Nanascale、Electrochem. Acta、Sensors and Actuators B以及RSC Adv.等学术杂志上发表SCI论文7篇，他引超过56次，授权发明专利11项。