Co-decoration of WS2 nanosheets with both Au and In2O3-nanoparticles for attaining the CO sensing in self-heating mode

Abstract

Two-dimensional materials such as WS2 nanosheets (NSs) have unique merits such as high surface area, good conductivity at low temperatures and good chemo-physical stability. In this study, we co-decorated In2O3 and Au NPs on WS2 NSs for CO gas sensing studies. The fabricated sensors were used in self-heating mode of operation at 25 °C, which can significantly decrease the power consumption. It was found that co-decorated gas sensor not only operates at a lower applied voltage, but also exhibits a higher sensing performance (sensitivity and selectivity), relative to bare WS2 NSs. On one hand, generation of In2O3-WS2 heterojunctions acted as notable sources of the resistance modulation and on the other hand, Au with its catalytic effect, significantly enhanced the dissociation of oxygen molecules and also offers many favorable adsorption sites for CO molecules. Therefore, we believe that co-decoration of WS2 is a reliable strategy to enhanced the sensing features in self-heating mode, which is highly demanded for devices with reduced power consumption.