Multiarray Gas Sensors Using Ternary Combined Ti₃C₂T_x MXene-Based Nanocomposites

Abstract

This paper reports chemiresistive multiarray gas sensors through the synthesized ternary nanocomposites, using a one-pot method to integrate two-dimensional MXene (Ti3C2T x ) with Ti-doped WO3 (Ti-WO3/Ti3C2T x ) and Ti3C2T x with Pd-doped SnO2 (Pd-SnO2/Ti3C2T x ). The gas sensors based on Ti-WO3/Ti3C2T x and Pd-SnO2/Ti3C2T x exhibit exceptional sensitivity, particularly in detecting 70% at 1 ppm acetone and 91.1% at 1 ppm of H2S. Notably, our sensors demonstrate a remarkable sensing performance in the low-ppb range for acetone and H2S. Specifically, the Ti-WO3/Ti3C2T x sensor demonstrates a detection limit of 0.035 ppb for acetone, and the Pd-SnO2/Ti3C2T x sensor shows 0.116 ppb for H2S. Simultaneous measurements with Ti-WO3/Ti3C2T x - and Pd-SnO2/Ti3C2T x -based sensors enable the evaluation of both the concentration and type of unknown target gases, such as acetone or H2S. Furthermore, density functional theory calculations are performed to clarify the role of Ti and Pd doping in enhancing the performance of Ti-WO3/Ti3C2T x and Pd-SnO2/Ti3C2T x nanocomposites. Theoretical simulations contribute to a deeper understanding of the doping effects, providing essential insights into the mechanisms underlying the enhanced gas response of the gas sensors. Overall, this work provides valuable insights into the gas-sensing mechanisms and introduces a novel approach for high-performance multiarray gas sensing.