MXene decorated tungsten trioxide nanocomposite-based sensor capable of detecting NO2 gas down to ppb-level at room temperature

Abstract

In this study, we reported the fabrication of WO3/Ti3C2TX nanocomposite-based sensing platform for the sub-ppb detection of NO2 gas at room temperature. The WO3/Ti3C2TX nanocomposite comprising WO3 nanoparticles and two-dimensional Ti3C2TX (MXene) was prepared using a one-step hydrothermal method. The morphological and structural characterizations of the WO3/Ti3C2TX nanocomposite were performed using field emission scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Raman spectroscopy, and nitrogen adsorption–desorption techniques. Further, the gas sensing properties of the WO3/Ti3C2TX nanocomposite-based sensors were investigated by estimating their sensing response and selectivity toward different target gases at room temperature. The WO3/Ti3C2TX nanocomposite-based sensor exhibited high response toward 15–500 ppb of NO2. In particular, the fabricated sensor showed a high response of 78, which was approximately eight times higher than the pristine WO3-based sensor (9.8) with short response time (182 s) and recovery time (75 s) toward 200-ppb NO2 at room temperature. The improved sensing characteristics were attributed to the synergistic behavior of WO3 nanoparticles and the layered morphology of 2D Ti3C2TX that provides large number of gas adsorption sites and highly conducting pathway for efficient charge transportation.