Room temperature ppb level-NO2 sensor based on WS2 with Fe -ni co-catalyst modification

Abstract

Rapid and highly sensitive detection of toxic gases at room temperature is crucial for ensuring health protection. However, the sensing materials reported thus far face the challenge of exhibiting relatively low response values at room temperature. In this study, we propose a facile synthesis method to prepare a Fe and Ni co-doped WS2 gas sensor capable of detecting nitrogen dioxide (NO2) at parts-per-billion (ppb) levels even at room temperature. The Fe-Ni@WS2 gas sensor exhibits excellent response performance (The response value is 81 at 1 ppm NO2). The incorporation of Fe and Ni into WS2 forms a Schottky junction that effectively regulates charge transfer behavior within the sensor material through conduction tunneling. Furthermore, the catalytic properties of Fe and Ni promote gas-sensitive reactions on the surface of WS2. This investigation elucidates the sensing mechanism of WS2 towards NO2 under bimetallic modification and provides an effective approach for constructing high-performance gas sensors through rational design of active sites.