Au-decorated In2O3 nanospheres/exfoliated Ti3C2Tx MXene nanosheets for highly sensitive formaldehyde gas sensing at room temperature

Formaldehyde (HCHO) is a significant air pollutant that is extremely harmful to both the human health and environments. Therefore, it is necessary to detect HCHO gas concentration and leakage in special regions at RT. This paper reported a facile preparation of Au-In2O3/Ti(3)C(2)T(x )MXene composites by in-situ reduction strategy and subsequent electrostatic self-assembly technology. An array of characterizations were performed to analyze the structure of the as-synthesized sensing material. The formed Au-In2O3/Ti3C2Tx MXene based sensor exhibited a prominent sensitivity (31 %) to 5 ppm HCHO at RT of 25 ? (21 % relative humidity). Moreover, the composites sensor possesses excellent long-term stability, the response/recovery rate is very rapid (5/4 s) and notable reproducibility (three cycles). The enhanced sensing properties could be put down to the catalytic effect of Au NPs, and the heterojunction and the cooperative effect between In2O3 and Ti3C2Tx MXene. Meanwhile, the potential sensing mechanism of the composite sensor to HCHO was explored via density functional theory (DFT) simulations. This research provides an efficient tactic for the prepared of high-response HCHO-sensing material for actual application.

Automated summary

In this study, a facile method was used to prepare Au-In2O3/Ti(3)C(2)T(x )MXene composites, which exhibited significant sensitivity and excellent stability to formaldehyde at room temperature. The potential sensing mechanism of the composite sensor to formaldehyde was explored through density functional theory (DFT) simulations, providing an efficient tactic for the preparation of high-response formaldehyde-sensing materials for practical applications.