UV-enhanced exfoliated MoS2/PtSe2 heterostructure for ultra-sensitive NO2 detection at room temperature

Abstract We report a MoS 2 /PtSe 2 heterostructure-based gas sensor for detecting trace levels of NO 2 gas at room temperature. Both MoS 2 and PtSe 2 were synthesized by mechanical exfoliation, and the heterostructure was prepared using deterministic dry transfer method. Comprehensive characterization was performed using optical microscopy, field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, high resolution transmission electron microscopy, Raman spectroscopy and atomic force microscopy. The lateral shape of the heterostructure efficiently adsorbed NO 2 molecules. The sensor exhibited limited response and recovery in dark conditions. However, under UV illumination, the sensor showed remarkable response of 2180% and 117% towards 800 ppb and 50 ppb NO 2 , respectively, with complete recovery. The theoretical limit of detection was found to be 3 ppb, and the sensitivity towards NO 2 sensing was 3.217% ppb −1 , which is noteworthy. Furthermore, the sensor demonstrated distinct selectivity, excellent repeatability and stability. These findings are expected to significantly advance ongoing research on TMDC-based heterostructures for gas sensing application.