Electrostatic Self-Assembly of Heterostructured In2O3/Ti3C2Tx Nanocomposite for High-Selectivity NO2 Gas Sensing at Room Temperature

• Published in: Chemosensors Vol. 13; no. 7; p. 249
• Main Authors: Guo, Yongjing, Zhang, Zhengxin, Feng, Hangshuo, Dai, Qingfu, Zhao, Qiuni, Duan, Zaihua, Guo, Shenghui, Yang, Li, Hou, Ming, Xia, Yi
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01.07.2025
• Subjects: Adsorption; Composite materials; Electrical conductivity; Electrical resistivity; Electrodes; Electron transfer; electrostatic self-assembly; Functional groups; gas sensing; Gas sensors; Gases; Heterojunctions; heterostructure; Hydrochloric acid; In2O3; Indium; Indium oxides; Metal carbides; Metal oxides; Microscopy; Morphology; MXene; MXenes; Nanocomposites; Nanoparticles; Nitrates; Nitrogen dioxide; Recovery time; Room temperature; Screen printing; Self-assembly; Sensors; Spectrum analysis; Temperature; Ti3C2Tx; Titanium carbide; Transition metals; VOCs; Volatile organic compounds; Zinc oxides; China; Japan
• ISSN: 2227-9040; 2227-9040
• DOI: 10.3390/chemosensors13070249

Owing to high electrical conductivity, layered structure, and abundant surface functional groups, transition metal carbides/nitrides (MXenes) have received enormous interest in the field of gas sensors at room temperature. In this work, we synthesize a heterostructured nanocomposite with indium oxide (In2O3) decorated on titanium carbide (Ti3C2Tx) nanosheets by electrostatic self-assembly and develop it for high-selectivity NO2 gas sensing at room temperature. Self-assembly formation of multiple heterojunctions in the In2O3/Ti3C2Tx composite provide abundant NO2 gas adsorption sites and high electron transfer activity, which is conducive to improving the gas-sensing response of the In2O3/Ti3C2Tx gas sensor. Assisted by rich adsorption sites and hetero interface, the as-fabricated In2O3/Ti3C2Tx gas sensor exhibits the highest response to NO2 among various interference gases. Meanwhile, a detection limit of 0.3 ppm, and response/recovery time (197.62/93.84 s) is displayed at room temperature. Finally, a NO2 sensing mechanism of In2O3/Ti3C2Tx gas sensor is constructed based on PN heterojunction enhancement and molecular adsorption. This work not only expands the gas-sensing application of MXenes, but also demonstrates an avenue for the rational design and construction of NO2-sensing materials.