Two-Dimensional Tungsten Diselenides Integrated on Paper Substrate for Highly Flexible and Sensitive Gas Sensor

This paper reports a highly sensitive nitrogen dioxide (NO₂) sensor based on two-dimensional (2D) tungsten diselenide (WSe₂) nanolayers. The WSe₂ nanolayers are integrated on a paper substrate by abrasion from their bulk form, which can be rapidly and cost-effectively completed. The 2D WSe₂ shows a high sensing response of ~1000% toward 10 ppm NO₂ exposure in air at room temperature, and at the same time, the paper substrate provides a high flexibility. The sensitivity of WSe₂-based sensor reaches to ~238.35% ppm^-1 at low concentration of NO₂ from 0.1 to 0.5 ppm. Our approach would be useful for constructing 2D nanomaterial-based highly sensitive gas sensor that can be fabricated by low-cost.