A novel sensing mechanism for resistive gas sensors based on layered reduced graphene oxide thin films at room temperature

In order to investigate the gas sensing mechanism of chemiresistors based on reduced graphene oxide (RGO), layered reduced graphene oxide was airbrushed onto interdigital electrodes (IDEs). Sensitive performances of all sensors with RGO sensitive films at room temperature were studied. Results showed that the total flow rate had a significant effect on the initial electric resistance of all sensors and their sensing responses to target gases as well. Besides, sensors with different quantities of deposited RGO solution were utilized to study the relationship among film thickness, sensing response and sensitivity. It was found that appropriate quantity of deposited RGO solution was critical for sensors' sensing response and sensitivity. Furthermore, a hybrid sensing mechanism including intra-sheet semiconducting characteristics and inter-sheet distance variation was proposed to explain some interesting phenomena. The proposed sensing mechanism can potentially enrich the applicable transduction mechanisms. (C) 2014 Elsevier B. V. All rights reserved.