The optimization of noble metal-modified MoSe2 nanoflowers gas sensor for hazardous NO2 detection

Recently, MoSe 2 has exhibited limited development in the field of gas sensors owing to its low sensitivity and slow response/recovery. Herein, various noble metals (Pt, Pd, and Ag) were employed to dope the MoSe 2 nanoflower for enhancing its sensing capability to NO 2 . Compared to Ag and Pd modification, the Pt doped-MoSe 2 sensor displayed higher sensitivity, faster response rate, and better selectivity. Moreover, the 2.5 %Pt-MoSe 2 sensor had a large sensitivity of 2.45 to 32 ppm NO 2 , good repeatability, and a low detection limit of 0.1 ppm at 110 °C. The improvement in the gas-sensing response can be attributed to the spillover effect and catalytic sensitization of Pt. Moreover, the first principle calculations for the adsorption energy and density of states have confirmed that the MoSe 2 material can adsorb NO 2 more effectively by Pt doping. The Pt-decorated MoSe 2 material exhibits a promising prospect in the field of NO 2 gas detection.