基于氧化物半导体团簇组装材料的低碳（C3以下）VOCs气体传感器研究

The sensitivity and selectivity as well as the independence on the relative humidity of the gas sensors based on semiconductor oxides must be improved greatly , which is a major and tremendous challenge, to detect accurately low concentration volatile organic compounds (VOCs). In the present project, a comprehensive strategy including of nanomaterial, doping modification and the first-principles calculation are used to develop a low-carbon (C3) VOCs gas sensor based on oxide semiconductor nanocluster -assembled materials and its sensitive mechanism. The "sensitization of the material structure" is achieved by designing and preparing the special nanostructures composed of cluster assembly materials using the liquid-phase method named as "bottom-up". The dopants and doping conditions are optimized to achieve "modified sensitization ". The structural unit of the typical oxide semiconductor cluster -assembled materials will be characterized and measured. The first-principles and molecular dynamics calculation will be adopted to calculate the assemble process of the clusters and to analysis the interaction between the sensing materials and some gases such as water vapor, oxygen and the testing gas. After the gas sensing mechanism is summarized, the sensing materials will be further designed and prepared to achieve ppb level detection for low-carbon VOCs such as methanol, formaldehyde, ethanol, acetaldehyde, ethylene and acetone. The performing of this project provides the experimental and theoretical basis for the application of VOCs gas sensors in many field such as atmospheric/ micro-environment monitoring, medical diagnosis and food safety.

面向低浓度挥发性有机化合物VOCs气体的准确检测，大幅度提升氧化物半导体传感器的灵敏度、选择性和抗湿性是急需解决的关键科学和技术问题。本项目融合氧化物半导体的纳米化、掺杂改性、表面修饰和第一性原理计算等策略，开展基于氧化物半导体纳米团簇组装材料的低碳（C3以下）VOCs气体传感器及其敏感机理研究。利用液相法“自下而上”的方式合成氧化物半导体纳米团簇组装材料，通过设计与制备特殊纳米结构实现“材料结构增感”；通过优化掺杂剂与掺杂条件实现“改性增感”；对已获得的典型氧化物半导体团簇组装材料进行结构单元解析，利用第一性原理和分子动力学的方法研究团簇的组装过程，分析水、氧以及待测气体与材料的相互作用；总结气敏机理，进一步设计和制备敏感材料，实现对低碳VOCs如甲醇、甲醛、乙醇、乙醛、乙烯和丙酮的ppb级检测，为VOCs气体传感器在大气/微环境监控、医疗诊断、食品安全等领域的应用奠定实验和理论基础。

本项目面向低浓度挥发性有机化合物VOCs气体的准确检测，融合氧化物半导体的纳米化、掺杂改性、表面修饰和理论分析等策略，开展基于氧化物半导体纳米团簇组装材料的低碳VOCs气体传感器及其敏感机理研究，大幅度提升氧化物半导体传感器的灵敏度、选择性和抗湿性。本项目利用液相法“自下而上”的方式合成氧化物半导体纳米团簇组装材料，通过设计与制备特殊纳米结构实现“材料结构增感”；通过优化掺杂剂与掺杂条件实现“改性增感”；分析了团簇的组装过程，分析水、氧以及待测气体与材料的相互作用；实现对低碳VOCs如二甲苯、乙炔、丙酮、三甲胺、三乙胺、正丁醇、2丁酮、正戊醇的ppm或ppb级检测，为VOCs 气体传感器在大气/微环境监控、医疗诊断、食品安全等领域的应用奠定实验和理论基础 。.通过本项目的研究，开发了基于不同种氧化物，如基于SnO2，WO3，ZnO，Cr2O3等单一氧化物以及复合氧化物敏感材料的气体传感器。研究结果表明：纳米线、纳米花、纳米簇等疏松结构具备高比表面积的同时有效避免了颗粒间的团聚，为气体的吸附、识别和扩散创造了良好条件，有利于气敏性能的提升；贵金属能够促进待测气体分子解离，加速表面反应，进而提升传感器灵敏度，可以一定程度上降低工作温度，并且双金属纳米颗粒具有比单一金属更好的催化性，在传感器灵敏度、稳定性、低功耗、抗湿性等方面均表现出巨大的潜力，所以通过构筑贵金属-氧化物半导体异质结构来对敏感材料进行修饰增感，完成其功能增感的要求是一种较理性的策略。本项目实施期间已成功制备了高灵敏度的气体传感器，传感器具有灵敏度高、检测下限低、选择性好、抗湿性强的特点，满足项目预期的研究目标。在项目运行期间，共发表标注基金资助号的SCI检索论文25篇，其中第一标注的论文13篇，申请国家发明专利16项。