Multiarray Gas Sensors Using Ternary Combined Ti₃C₂T MXene-Based Nanocomposites

This paper reports chemiresistive multiarray gas sensors through the synthesized ternary nanocomposites, using a one-pot method to integrate two-dimensional MXene (Ti₃C₂T) with Ti-doped WO₃ (Ti-WO₃/Ti₃C₂T) and Ti₃C₂T with Pd-doped SnO₂ (Pd-SnO₂/Ti₃C₂T). The gas sensors based on Ti-WO₃/Ti₃C₂T and Pd-SnO₂/Ti₃C₂T 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 sensor demonstrates a detection limit of 0.035 ppb for acetone, and the Pd-SnO₂/Ti₃C₂T sensor shows 0.116 ppb for H₂S. Simultaneous measurements with Ti-WO₃/Ti₃C₂T- and Pd-SnO₂/Ti₃C₂T-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 and Pd-SnO₂/Ti₃C₂T 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.