Crystal-phase and Surface-Structure Engineering of MoS₂ for Improving Gas Sensor Performance at Room Temperature

Abstract

Transition metal dichalcogenides are interesting materials with the features of the layered structure and high electrical conductivity. It is known that the metal dichalcogenides represented by molybdenum disulfide (MoS₂) have two structures, a semiconductor 2H type, and a metal 1T type, and the physicochemical properties of different phase compositions are dramatically changed. MoS₂ has excellent flexibility, good adsorption ability, and reactivity at room temperature, offering a potential possibility for wearable sensor device development. To increase the number of MoS₂ active sites and realize the surface and phase engineering of 1T/2H-MoS₂, a series of surface modification methods, such as ethylene glycol intercalation under solvothermal treatment, oxygen plasma treatment, and elements substitution, were carried out. Different kinds of gasses have been successfully detected by using MoS₂ as a sensor material at room temperature, which increases its possibility to be one of the suitable candidates for novel and wearable sensor devices material.