Highly sensitive and selective H2S gas sensor based on TiO2 thin films
Highly sensitive and selective H2S gas sensor based on TiO2 thin films
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DOI：
10.1016/j.apsusc.2021.149281
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发表时间：
2021-02-21
影响因子：
6.7
通讯作者：
Aswal, D. K.
中科院分区：
文献类型：
--
作者：
Nagmani;Pravarthana, D.;Aswal, D. K.
硫化氢（H2S）气体传感器具有非常高的灵敏度、选择性和快速响应，在实际工业应用中具有很高的要求。然而，由于现有传感器材料的高成本制造、差的选择性和稳定性，实现它仍然是一个挑战。在这项工作中，我们报告了纳米TiO2薄膜为基础的高选择性的H2S传感器的硅衬底上，表现出上级传感器响应类似于112000%和类似于85%，在50 ppm和100 ppb浓度的H2S气体，分别在100 ℃时操作。此外，它具有快速的响应时间（类似于48秒）和快速的恢复时间（5分钟），在H2S气体传感长期稳定。TiO_2薄膜对H_2S气体的敏感性与其表面粗糙度和薄膜表面过量的化学吸附氧有关。因此，发现具有适当粗糙度和缺陷的TiO 2薄膜在实现H2S气体传感器在较低ppm检测下的更好的H2S选择性和灵敏度特性方面起着重要作用。
Hydrogen Sulfide (H2S) gas sensors with very high sensitivity, selectivity, and quick responses are highly demanding for practical industrial applications. However, achieving it remains a challenging due to high-cost fabrication, poor selectivity, and stability of existing sensor materials. In this work, we report the nanocrystalline TiO2 thin film based highly selective H2S sensor on a silicon substrate, which exhibits superior sensor response of similar to 112000% and similar to 85% at 50 ppm and 100 ppb concentration of H2S gas, respectively when operated at 100 degrees C. Also, it exhibits quick response time (similar to 48 s) and fast recovery time (5 min) with long term stability in H2S gas sensing. The sensitivity of H2S gas on the TiO2 film is related to its surface roughness and excessive chemisorbed oxygen on the surface of the film. Thus, it was found that TiO2 thin film with appropriate roughness and defects plays a significant role in achieving a much better H2S selectivity and sensitivity properties at lower ppm detection for the H2S gas sensor.