Si Renjun, Xie Xiujuan, Li Tianyu, Zheng Jun, Cheng Chao, Huang Shouguo, Wang Chunchang
Laboratory of Dielectric Functional Materials, School of Physics & Materials Science, Anhui University, Hefei 230601, China.
Institute of Physical Science and Information Technology, Anhui University, Hefei 230601, China.
ACS Sens. 2020 May 22;5(5):1345-1353. doi: 10.1021/acssensors.9b02586. Epub 2020 Apr 20.
Nanomaterials of TiO, (KNa)NbO, and the TiO/(KNa)NbO nanocomposite were successfully synthesized by a hydrothermal method. Impedance-type humidity sensors were fabricated based on these materials. Our results reveal that the impedance of the TiO/(KNa)NbO sensor changes by 5 orders of magnitude with an ultrahigh sensing response of = 166 470 recorded at 100 Hz in the tested relative humidity (RH) range of 12-94%. This value is almost 2 and 4 orders of magnitude larger than that of the (KNa)NbO and TiO sensors, respectively. Interestingly, satisfactory response/recovery time (25/38 s, within 5 min), very small hysteresis (<5%), excellent stability, and good repeatability were also achieved in the TiO/(KNa)NbO sensor. The improved sensing properties are ascribed to the synergistic effect of TiO/(KNa)NbO heterojunction, which contributes the impedance that is susceptible to environmental humidity. This work underscores that it is a facile way to boost humidity-sensing performance by constructing proper nanocomposites.
通过水热法成功合成了TiO₂、(KNa)NbO₃纳米材料以及TiO₂/(KNa)NbO₃纳米复合材料。基于这些材料制备了阻抗型湿度传感器。我们的结果表明，在12 - 94%的测试相对湿度（RH）范围内，TiO₂/(KNa)NbO₃传感器的阻抗变化了5个数量级，在100 Hz时记录到的超高传感响应为 = 166470。该值分别比(KNa)NbO₃和TiO₂传感器的值大近2个和4个数量级。有趣的是，TiO₂/(KNa)NbO₃传感器还实现了令人满意的响应/恢复时间（25/38 s，在5分钟内）、非常小的滞后（<5%）、优异的稳定性和良好的重复性。传感性能的改善归因于TiO₂/(KNa)NbO₃异质结的协同效应，其贡献了易受环境湿度影响的阻抗。这项工作强调了通过构建合适的纳米复合材料来提高湿度传感性能是一种简便的方法。
