Understanding the chemical reception and electronic transduction mechanism in gas sensing with sulfide colloidal quantum dots

了解硫化物胶体量子点气体传感中的化学接收和电子转导机制

• 批准号: 410284094
• 负责人: Dr. Nicolae Barsan
• 金额: --
• 依托单位: Institut für Physikalische und Theoretische Chemie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/410284094?language=en
• 关键词: Understanding; chemical; reception; electronic; transduction

Today, there is a need for low-cost and highly efficient sensors to detect low concentrations (ppb level) of toxic gases. Currently, traditional chemiresistive sensors based on semiconducting oxides (SMOX) are widely used due to their excellent sensor responses, robustness and low cost. SMOX based sensors, however, require high operation temperatures between 200 °C and 600 °C resulting in both high power consumption and safety issues. As a result, there is a worldwide effort to produce rapid, sensitive, low temperature-operating gas sensors. Metal sulfides are emerging as promising materials. At room temperature, sensors based on PbS show high responses to NO2 and NH3, while ZnS is known to show a high response to H2S. For even better results, a new development is the use of sulfide colloidal quantum dots (CQDs) for gas sensing. CQDs have an extremely large surface-to-volume ratio capable of active interaction with target gas molecules. In addition, the size controlled synthesis of sulfide CQDs allows electronic and optical properties to be changed. The goal of this project is to understand the chemical reception of sulfide CQDs. The results of other metal sulfides, e.g. Bi2S3, SnS, and ZnS will be compared to those for PbS. The surface reaction mechanisms and possible sources of instability will be identified using operando diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy. Operando work function measurements will provide insight into the charge transfer processes associated with the surface chemistry. The results will provide the input for a sensing model. This model will serve as a basis for understanding gas sensing with metal sulfides.

如今，需要低成本且高效的传感器来检测低浓度（ppb 级）的有毒气体。目前，基于半导体氧化物（SMOX）的传统化学电阻传感器因其优异的传感器响应、鲁棒性和低成本而被广泛使用。然而，基于 SMOX 的传感器需要 200 °C 至 600 °C 之间的高工作温度，从而导致高功耗和安全问题。因此，全世界都在努力生产快速、灵敏、低温工作的气体传感器。金属硫化物正在成为有前途的材料。在室温下，基于 PbS 的传感器对 NO2 和 NH3 表现出高响应，而 ZnS 对 H2S 表现出高响应。为了获得更好的结果，一项新的发展是使用硫化物胶体量子点 (CQD) 进行气体传感。 CQD 具有极大的表面积与体积比，能够与目标气体分子发生主动相互作用。此外，硫化物 CQD 的尺寸控制合成可以改变电子和光学特性。该项目的目标是了解硫化物 CQD 的化学接收。其他金属硫化物的结果，例如Bi2S3、SnS 和 ZnS 将与 PbS 进行比较。表面反应机制和可能的不稳定来源将使用操作漫反射红外傅里叶变换（DRIFT）光谱来识别。操作功函数测量将提供对与表面化学相关的电荷转移过程的深入了解。结果将为传感模型提供输入。该模型将作为理解金属硫化物气体传感的基础。