Wool-Based Carbon Fiber/MoS2 Composite Prepared by Low-Temperature Catalytic Hydrothermal Method and Its Application in the Field of Gas Sensors

Abstract

Under the background of the Paris Agreement on reducing greenhouse gases, waste wools were converted into wool carbon fiber (WCF) and WCF-MoS₂ composites by low-temperature catalytic hydrothermal carbonization. Their structures and gas-sensing performances were studied for the first time. Due to the existence of heterojunctions, the responses of the WCF-MoS₂ composite to the five analytes were 3-400 times those of MoS₂ and 2-11 times those of WCF. Interestingly, because of the N, P, and S elements contained in wools, the WCF prepared by the hydrothermal method was realized the doping of N, P, and S, which caused the sensing curves of WCF to have different shapes for different analytes. This characteristic was also well demonstrated by the WCF-MoS₂ composite, which inspired us to realize the discriminative detection only by a single WCF-MoS₂ sensor and image recognition technology. What's more, the WCF-MoS₂ composite also showed a high sensitivity, a high selectivity, and a rapid response to NH₃. The response time and the recovery time to 3 ppm NH₃ were about 16 and 5 s, respectively. The detection of limit of WCF-MoS₂ for NH₃ was 19.1 ppb. This work provides a new idea for the development of sensors and the resource utilization of wool waste.