Chemiresistive NH Sensor of Cotton-Stalk- Based Carbon@MoS Composites Promoted by Heterojunction

Abstract

Under the background of the global low carbon development, in order to prevent the carbon in cotton stalks from returning to the atmospheric environment in the form of greenhouse gas, cotton stalks were used as a carbon source to prepare cotton straw-based carbon (CSC). Furthermore, CSC@MoS2 composites were prepared by hydrothermal reaction and used as a gas sensor for the first time. The structure and morphology of the CSC and CSC@MoS2 composites were characterized by scanning electron microscope, transmission electron microscope, X-ray diffraction, Raman spectroscopy, and Fourier transform infrared spectroscopy. The CSC@MoS2 sensor exhibits a high sensitivity to NH3, fast response (< 26 s), and recovery (< 2.2 s). No matter whether after three months or in different humidity environments, the response fluctuation of the CSC@MoS2 sensor to NH3 is less than 5%, showing good long-term stability and antihumidity interference ability. Good repeatability is also shown between the different CSC@MoS2 sensors. This study not only provides a new reference for the low-carbon treatment and resource utilization of crop straw represented by cotton stalk but also provides a new path for the development of the gas sensor.