School of Mechanical Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 03722, Republic of Korea.
ACS Sens. 2020 Mar 27;5(3):754-763. doi: 10.1021/acssensors.9b02310. Epub 2020 Feb 27.
Among various metal oxides, titanium dioxide (TiO) has received considerable interest as a gas-sensing material owing to its high reliability at high operating temperatures. Nonetheless, TiO generally has low sensitivity to target gases. In particular, TiO-based sensors have difficulty in sensitively detecting benzene, toluene, and xylene (referred to as BTX). Moreover, the reported TiO-based sensors have not simultaneously satisfied the demand for tens of ppb BTX detection and operation with low power consumption. This work proposes a BTX sensor using cobalt porphyrin (CoPP)-functionalized TiO nanoparticles as a sensing material on a suspended microheater fabricated by bulk micromachining for low power consumption. TiO nanoparticles show an enhanced sensitivity (245%) to 10 ppm toluene with CoPP functionalization. The proposed sensor exhibits high sensitivity to BTX at concentrations ranging from 10 ppm down to several ppb. The high reliability of the sensor is also explored through the long-time operation with repeated exposure to 10 ppm toluene for 14 h.
在各种金属氧化物中，二氧化钛 (TiO) 因其在高温下的高可靠性而作为气体传感材料受到了相当大的关注。然而，TiO 通常对目标气体的灵敏度较低。特别是，基于 TiO 的传感器难以灵敏地检测苯、甲苯和二甲苯（简称 BTX）。此外，报道的基于 TiO 的传感器尚未同时满足对数十 ppb BTX 检测和低功耗运行的需求。本工作提出了一种使用钴卟啉 (CoPP)-功能化 TiO 纳米粒子作为传感材料的 BTX 传感器，该传感器基于体微机械加工制造的悬浮微加热器，以实现低功耗。CoPP 功能化使 TiO 纳米粒子对 10 ppm 甲苯的灵敏度提高了 245%。所提出的传感器对 BTX 的灵敏度在 10 ppm 到几个 ppb 的浓度范围内都很高。通过长时间重复暴露于 10 ppm 甲苯 14 小时的操作，也探索了传感器的高可靠性。
