Spagnoli Elena, Valt Matteo, Gaiardo Andrea, Fabbri Barbara, Guidi Vincenzo
Department of Physics and Earth Sciences, University of Ferrara, Via Saragat 1/C, 44122 Ferrara, Italy.
MNF-Micro Nano Facility, Sensors and Devices Center, Bruno Kessler Foundation, Via Sommarive 18, 38123 Trento, Italy.
Nanomaterials (Basel). 2023 Oct 5;13(19):2708. doi: 10.3390/nano13192708.
Recently, the influence of Nb addition in the oxide solid solution of Sn and Ti was investigated with regard to the morphological, structural and electrical properties for the production of chemoresistive gas sensors. (Sn,Ti,Nb)O-based sensors showed promising features for ethanol monitoring in commercial or industrial settings characterized by frequent variation in relative humidity. Indeed, the three-metal solid solution highlighted a higher response level vs. ethanol than the most widely used SnO and a remarkably low effect of relative humidity on the film resistance. Nevertheless, lack of knowledge still persists on the mechanisms of gas reaction occurring at the surface of these nanostructures. In this work, Diffuse Reflectance Infrared Fourier Transform spectroscopy was used on SnO- and on (Sn,Ti,Nb)O-based sensors to combine the investigations on the transduction function, i.e., the read-out of the device activity, with the investigations on the receptor function, i.e., compositional characterization of the active sensing element in real time and under operating conditions. The sensors performance was explained by probing the interaction of HO and ethanol molecules with the material surface sites. This information is fundamental for fine-tuning of material characteristics for any specific gas sensing applications.
最近，针对用于制作化学电阻式气体传感器的形态、结构和电学性能，研究了在Sn和Ti的氧化物固溶体中添加Nb的影响。基于(Sn,Ti,Nb)O的传感器在商业或工业环境中监测乙醇方面表现出良好的特性，这些环境的特点是相对湿度频繁变化。事实上，这种三金属固溶体对乙醇的响应水平高于最广泛使用的SnO，并且相对湿度对薄膜电阻的影响非常低。然而，对于这些纳米结构表面发生的气体反应机制，仍然缺乏了解。在这项工作中，对基于SnO和(Sn,Ti,Nb)O的传感器使用了漫反射红外傅里叶变换光谱，将对转换功能（即器件活性的读出）的研究与对受体功能（即在操作条件下实时对活性传感元件进行成分表征）的研究结合起来。通过探测HO和乙醇分子与材料表面位点的相互作用来解释传感器的性能。这些信息对于针对任何特定气体传感应用微调材料特性至关重要。
