P2GS.4 - WS2-decorated rGO for Quasi-room Temperature Gas Sensing Applications

Abstract

We report on the NO2 and humidity chemoresistive gas responses of reduced graphene oxide (rGO) and WS2-decorated rGO (GO/WS2).Films are prepared by drop casting a solution of GO and WS2 suspended nanoflakes in ethanol, on Si3N4 patterned substrates to yield a homogeneous dispersion of WS2 on the GO matrix as shown by HRTEM microstructural characterization.After thermal reduction at 70°C, rGO and rGO/WS2 gas sensing response are compared, exposing the films to NO2 (2-10 ppm) in dry air and 60% Relative Humidity (R.H.) at quasi room temperature (i.e.25°C and 50°C).WS2 addition improves the stability of the baseline, and poses improved sensitivity to NO2.Finally, the effect of visible light illumination on gas desorption mechanism is examined, observing a positive effect on the base line recovery after gas evacuation.