Temperature‐Modulated Selective Detection of Part‐per‐Trillion NO<sub>2</sub> Using Platinum Nanocluster Sensitized 3D Metal Oxide Nanotube Arrays
Zhilong Song, Wenying Tang, Zhesi Chen, Zhu’an Wan, Chak Lam Jonathan Chan, Chen Wang, Wenhao Ye, Zhiyong Fan
Abstract
Abstract Semiconductor chemiresistive gas sensors play critical roles in a smart and sustainable city where a safe and healthy environment is the foundation. However, the poor limits of detection and selectivity are the two bottleneck issues limiting their broad applications. Herein, a unique sensor design with a 3D tin oxide (SnO 2 ) nanotube array as the sensing layer and platinum (Pt) nanocluster decoration as the catalytic layer, is demonstrated. The Pt/SnO 2 sensor significantly enhances the sensitivity and selectivity of NO 2 detection by strengthening the adsorption energy and lowering the activation energy toward NO 2 . It not only leads to ultrahigh sensitivity to NO 2 with a record limit of detection of 107 parts per trillion, but also enables selective NO 2 sensing while suppressing the responses to interfering gases. Furthermore, a wireless sensor system integrated with sensors, a microcontroller, and a Bluetooth unit is developed for the practical indoor and on‐road NO 2 detection applications. The rational design of the sensors and their successful demonstration pave the way for future real‐time gas monitoring in smart home and smart city applications.