Room-temperature nitrogen dioxide gas sensor based on graphene oxide nanoribbons decorated with MoS2 nanospheres

Nitrogen dioxide (NO2) has harmful effects on human health as well as the environment, and hence, developing low cost and power consumption of NO2 sensors is of great importance. Combed shape gold electrodes sputtered on the surface of silicon substrate were modified with narrow graphene oxide nanoribbons and MoS2 nanospheres to fabricate the gas sensor; synthesized by longitudinal unzipping of carbon nanotubes. Under static conditions and room temperature, we could detect NO2 with concentrations as low as ten ppm with 33% and 250% sensitivity for pristine and MoS2-decorated graphene oxide nanoribbon thin film, respectively. The gas-sensing mechanism has been studied using density functional theory in combination with XRD, TEM, SEM, FTIR, and Raman results. In the case of pristine graphene oxide nanoribbons, detection is based on the adsorption of gas molecules at the defect sites and charge transfer of the molecules. In contrast, the charge transfer and change in the Schottky barrier are dominant in the decorated sensor. These results are expected to provide new perspectives toward detecting of nitrogen dioxide on the surface of MoS2 nanospheres@graphene oxide nanoribbon-modified electrodes with a low detection limit. Graphical abstract