State Key Laboratory of Electronic Thin Films and Integrated Devices, School of Optoelectronic Science and Engineering, University of Electronic Science and Technology of China (UESTC), Chengdu 610054, China.
Key University Laboratory of Sensing Technology and Control of Shandong Province, School of Information and Electronic Engineering, Shandong Technology and Business University (SDTBU), Yantai 264000, China.
ACS Sens. 2021 Aug 27;6(8):2858-2867. doi: 10.1021/acssensors.1c00132. Epub 2021 Jun 29.
Titanium carbide (TiCT) with a distinctive structure, abundant surface chemical groups, and good electrical conductivity has shown great potential in fabricating superior gas sensors, but several challenges, such as low response kinetics, poor reversibility, and serious baseline drift, still remain. In this work, γ-poly(l-glutamic acid) (γ-PGA) with a blocking effect is exploited to modify TiCT, thereby stimulating the positive response behavior of TiCT and improving its gas sensing performance. On account of the unique synergetic interaction between TiCT and γ-PGA, the response of the flexible TiCT/γ-PGA gas sensor to 50 ppm NOhas been improved to a large extent (average 1127.3%), which is 85 times that of TiCT (only 13.2%). Moreover, the as-fabricated TiCT/γ-PGA sensor not only exhibits a shorter response/recovery time (average 43.4/3 s) compared with the TiCT-based sensor (∼18.5/18.3 min) but also shows good reversibility and repeatability (relative standard deviation (RSD) <1%) at room temperature within 50% relative humidity (RH). The improved gas sensing properties of the TiCT/γ-PGA sensor can be attributed to the enhancement of effective adsorption and the blocking effect assisted by water molecules. Furthermore, the gas sensing response of the TiCT/γ-PGA sensor is studied at different RHs, and humidity compensation of the sensor is carried out using the multiple regression method. This work demonstrates a novel strategy to enhance the gas sensing properties of TiCT by γ-PGA modification and provides a new way to realize highly responsive gas detection at room temperature.
碳化钛（TiCT）具有独特的结构、丰富的表面化学基团和良好的导电性，在制造高性能气体传感器方面显示出巨大的潜力，但仍存在一些挑战，例如响应动力学低、可逆性差和严重的基线漂移。在这项工作中，利用具有阻塞效应的γ-聚（L-谷氨酸）（γ-PGA）来修饰 TiCT，从而刺激 TiCT 的正响应行为并改善其气体传感性能。由于 TiCT 和 γ-PGA 之间独特的协同相互作用，柔性 TiCT/γ-PGA 气体传感器对 50ppmNO 的响应得到了很大程度的提高（平均提高 1127.3%），是 TiCT 的 85 倍（仅 13.2%）。此外，所制造的 TiCT/γ-PGA 传感器不仅表现出比基于 TiCT 的传感器（约 18.5/18.3min）更短的响应/恢复时间（平均 43.4/3s），而且在室温下 50%相对湿度（RH）范围内还表现出良好的可逆性和重复性（相对标准偏差（RSD）<1%）。TiCT/γ-PGA 传感器气体传感性能的提高归因于水分子辅助下有效吸附的增强和阻塞效应。此外，还研究了 TiCT/γ-PGA 传感器在不同 RH 下的气体传感响应，并采用多元回归法对传感器进行湿度补偿。这项工作展示了一种通过 γ-PGA 修饰来增强 TiCT 气体传感性能的新策略，并为在室温下实现高灵敏度气体检测提供了新途径。
