Laser-induced enhancement for the detection of isopropyl alcohol in V₂CTx MXene films

The development of efficient gas sensing material having good sensitivity, working at room temperature, and quick response and recovery is imperative for indoor environmental monitoring, especially for detecting volatile organic compounds (VOC). There has been significant interest in 2D materials for gas sensors owing to their high surface area. However, the sensitivity of these materials is limited by the restacking of the thin layers in conventional chemical exfoliation and deposition routes. We focus here on MXene as a detection surface and investigate an efficient route to prepare 3D-architectonic films having improved sensing capabilities using spatially and temporally controlled-pulse laser irradiation. For this purpose, V₂CTx MXene has been synthesized by an HF free synthesis route and has been applied for isopropyl alcohol detection with subsequent laser treatment. By applying a variable dose of laser power (1 mW to 10 mW), the sensing performance has been optimized. The laser treated sensor (laser power 2.5 mW) has shown a high response of ∼116% towards 500 ppm of isopropyl alcohol compared to that of as deposited V₂CTx MXene (∼28%). This enhancement was observed due to the formation of connected three dimensional structures produced by laser irradiation. Due to the formation of hierarchical 3D architecture, the sensor has shown very fast response and recovery within 3.32 sec and 3.36 sec, respectively. This study presents valuable insights into the laser irradiation technique as a scalable, contactless, and chemical free technique to produce 3D architecture MXene films with superior gas sensing performance.