Early Warning of Coal Spontaneous Combustion: A Study of CO Response Mechanism Based on PANI/Ti 3 AlC 2 Composite Gas Sensing Film

• Published in: ChemistrySelect (Weinheim) Vol. 7; no. 26
• Main Authors: Wang, Xu‐Wei, Hu, Xiang‐Ming, Liang, Yun‐Tao, Wu, Ming‐Yue, Xue, Di, Yu, Xiao‐Xiao, Liu, Jin‐Di, Dong, Hao, Luo, Chong‐Yang, Yang, Zhen‐Yu
• Format: Journal Article
• Language: English
• Published: 14.07.2022
• ISSN: 2365-6549; 2365-6549
• DOI: 10.1002/slct.202201563

Abstract Fire accidents caused by coal spontaneous combustion seriously affect the production safety of coal mines. Carbon monoxide (CO) is an important gas indicator used for monitoring and early warning detection of coal spontaneous combustion. Therefore, the development of CO sensors with low cost, low power consumption, and environmental protection is highly desirable. This can be achieved through deep optimization of semiconductor CO sensors as alternatives to infrared detection and electrochemical sensors. In this paper, Ti 3 AlC 2 (MXenes)/polyaniline (PANI) composite were studied as semiconductor CO sensors. The optimal added amount of Ti 3 AlC 2 was determined by testing at gas concentrations of 100 ppm and 150 ppm CO. The morphology, structure, and chemical characteristics of each composite were analyzed by field emission transmission electron microscopy (SEM‐EDS), Fourier infrared spectrometry, UV‐visible near infrared spectrophotometer, X‐ray photoelectron spectroscopy (XPS), and thermogravimetric techniques. Compared to pure PANI material, the SEM‐EDS experimental results showed Ti 3 AlC 2 with an increased number of PANI flake structures, generating more CO gas adsorption sites. The XPS results showed Ti 3 AlC 2 was able of improving the protonation and oxidation degree of PANI, thereby improving its gas sensing performance. Accordingly, a sensing mechanism model was proposed, revealing the excellent sensing performance originating from the gas sensing enhancement effect of heterojunction. In sum, this study provided a scientific basis for the design and development of CO sensors with low cost, low power consumption, and future environmental protection.