基于 In2-2xZnySnxO3 复合氧化物的高性能甲醛气体传感器研究

Indoor air pollution has an increasing trend, resulting in bad effect on health and environment. Formaldehyde gas is the main pollutants in the indoor air. An easy operating, selective and portable gas sensor is required urgently to real-time detect it sensitively and accurately. Sensing devices based on semiconductor metal oxides have some advantages, including high response, easy operation and can be miniaturized, integrated and intelligentized facilely. They can play a key role in indoor air quality detection. .A tunable synthesis of size- and shape-controlled sensing materials, In2-2xZnySnxO3, would be employed to realize the real-time detection of formaldehyde gas. On one hand, the synergetic effect and band structure of the three kinds of cationic would play an effective role to improve the selectivity of the gas sensor based on the complex metal oxide. Furthermore, the phase purity and morphology of the complex oxide will be systematically investigated by adjusting the reaction parameters, such as reaction temperature, reaction time, correlations of the In/Sn/Zn ratio, the addition of surfactant et al. And the final material with high-index facets having high densities of atom steps, ledges, kinks and dangling bonds would be obtained in this project. And it is an effective strategy to improve the sensitivity and selectivity of sensors. Finally, the details and the mechanisms behind the formation of the differently shaped materials will be sufficiently studied. The influence of material microstructure on its gas-sensing properties will be discussed in depth. In one word, the experimental and theoretical results found in this proposal could be provided to design gas-sensing materials with more excellent performance..

室内空气安全对民生极其重要，甲醛是主要污染物之一，实时、灵敏而准确地对其检测急需开发便携式气体传感器。半导体金属氧化物气体传感器满足对甲醛进行实时检测的便携式需求，但其灵敏度还难以满足标准检测的要求，选择性和气敏机理的理解还存在挑战，需要进一步研究。.高电子迁移率的In2O3是优异的气敏材料，为了进一步提高其对甲醛的选择性检测，本项目拟：（1）通过Zn/Sn共掺调节与甲醛匹配的能带结构，设计合成In2-2xZnySnxO3（x>y）氧化物，协同In3+、Sn4+和Zn2+离子的催化效应，提高材料对甲醛气体的选择性；（2）借助调控合成反应参数，制备以高指数晶面为暴露晶面的气敏材料，提高材料的灵敏度；（3）系统研究暴露晶面与材料气敏性能的关系，探究气敏材料的敏感机理和高性能气敏材料设计的影响因素；（4）基于所制备的高性能气敏材料，构建选择性好、灵敏度高的便携式气体传感器，满足室内空气质量检测。

甲醛是一种原生质毒物，对人体健康的危害具有长期性、潜伏性、隐蔽性的特点。目前室内环境的污染问题已经受到了高度的重视，污染物的检测问题也得到了很多人的关注。而对污染物进行实时、准确的现场检测和识别是控制室内空气质量的关键技术。因此，探索新的高精度、高可靠性的优良敏感材料，改进元件结构及其制备工艺来改善和提高传感器的响应特性、选择性和稳定性，是甲醛气体传感器进一步发展的关键。我们选择具有多种组分所形成的固溶体作为敏感材料，同时引入In3+、Sn4+、Zn2+三种金属离子而形成多元氧化物In2-2xZnySnxO3，构建出对甲醛敏感、性能优异的新型气体传感器。本课题重点研究了影响多元化合物的各种实验因素，在不同实验条件下得到了一系列具有不同微观形貌的化合物，并系统研究了这些化合物的敏感性能，探讨了材料不同暴露晶面对其最终敏感性能的影响，揭示了多元金属氧化物形成过程中晶体生长的一般规律及材料微观结构与其敏感性能之间的构效关系。2015年度合成出具有规则形貌、尺寸可控的三元金属氧化物CdIn2O4和ZnSn2O4以及ZnGa2O4，完成了该系列化合物气体敏感性能的研究。发表SCI论文3篇，EI论文1篇，中文核心期刊2篇。2016年度继续按照计划完成了四元金属氧化物合成条件的探索，随着实验条件的改变，得到片状CdO和立方体In2O3，发表SCI论文1篇；2017年度继续上年度的研究，按照计划制得四元金属氧化物，并完成了其气体传感性能的系统测试，投稿SCI论文4篇。