Fabrication of flexible La-MoS2 hybrid-heterostructure based sensor for NO2 gas sensing at room temperature

Abstract

Transition metal dichalcogenides (TMDs) materials are from the two-dimensional (2D) materials family and have many benefits, comprising high carrier mobility and conductivity, high optical transparency, outstanding mechanical flexibility, and chemical stability, and are also favorable gas sensing materials because of their high surface-area-to-volume ratio. Nevertheless, their low gas-sensing performance in terms of low response, partial recovery, and poor selectivity obstruct the apprehension as high-performance 2D TMDs gas sensing materials. At this time, we explain the enhancement in gas-sensing performance of molybdenum disulfide (MoS₂) nanoflakes (NF) by decorating with Lanthanum (La) at room temperature (25 °C). Our experiments show that the dynamic sensing response of the La decorated few-layered MoS₂ (La@MoS₂) sensor increases by ∼6 times than the pristine few-layered MoS₂, which positions it first-ever reported values for NO₂ gas detection. The sensitivity of the MoS₂ and La@MoS₂ found 0.627 and 3.346 ppm^-1, respectively, towards NO₂ gas. It is noteworthy that La has introduced to MoS_2, and its selectivity towards the volatile organic compounds (VOCs) and other toxic gases improved drastically. Our outcomes show that the suggested method represents a successful approach for improving the gas sensing response of 2D TMDs sensors.