基于ZIF8/rGO的高性能NO_(2)室温传感器

High Performance of Room-temperature NO_(2) Gas Sensor Based on ZIF8/rGO

二氧化氮气体是一种常见的大气污染物,对自然环境和人类健康造成严重的危害,开发检测该类有毒有害气体的高效检测设备势在必行。新型复合薄膜气体传感器可以在常温下对二氧化氮进行高选择性、高灵敏度检测,为自然环境和人类健康保驾护航。本工作采用化学沉淀法和超声法制备了多孔、高比表面积的ZIF8/还原氧化石墨烯(ZIF8/rGO)复合材料,以此为气敏材料构建NO_(2)传感器,并系统研究了其在室温下对NO_(2)的气敏性能,进一步探讨了ZIF8/rGO气敏传感器感应NO_(2)的可能机理。气敏实验结果表明:ZIF8/rGO气敏传感器对50×10^(-6) NO_(2)的响应达到34.77%,是纯rGO气敏传感器的3.2倍。ZIF8/rGO传感器在4个可逆循环测试中表现出较好的可重复性,RSD(Relative Standard Deviation)为3.9%。此外,ZIF8/rGO传感器表现出优秀的长期稳定性(RSD为2.5%)、选择性和低的检出限(3.8×10^(-8))。室温下灵敏感应NO_(2)的气敏性能主要归因于ZIF8的多孔结构和超大的比表面积以及rGO的优越性能。本工作将为ZIF8/rGO作为气敏材料检测有毒有害的NO_(2)气体提供新思路。

As a common air pollutant,nitrogen dioxide(NO_(2))gas does serious harm to the natural environment and human health.Therefore,it is imperative to develop efficient detection methods for detecting such toxic and harmful gases.Developing a new type of composite film gas sensor to achieve high selectivity and high sensitivity detection of nitrogen dioxide at room temperature has become a research hotspot.Here,we prepared zeolitic imidazolate framework 8/reduced graphene oxide(ZIF8/rGO)composite with porosity and large specific surface area through chemical precipitation and ultrasonic method.Based on this materials,an NO_(2) sensor was constructed and then evaluated at room-temperature. Its possible mechanism of sensing NO_(2) was explored. The results showed that ZIF8/rGO sensor presented a response of 34.77% toward 50×10^(-6) NO_(2), which was 3.2-fold of pure rGO senor. Meanwhile it exhibited excellent repeatability after 4 reversible cycles with the relative standard deviation (RSD) only 3.9% and remarkable long-term stability in four-week test with the RSD of 2.5%, accompanied outstanding selectivity toward NO_(2) and a low limit of detection of 3.8×10^(-8). These hypersensitive properties at room temperature were attributed to its porous structure and large specific surface and high performance of rGO. This work offers a new idea for efficiently detecting poisonous NO_(2) based on ZIF8/rGO.