Fabrication of CO2 Gas Sensors Using Graphene Decorated

This paper describes the fabrication and characterization of graphene based carbon dioxide (CO2) gas sensors. Graphene was synthesized by thermal decomposition of SiC. The resistivity CO2 gas sensors were fabricated by pure graphene and graphene decorated Au nanoparticles (NPs). The Au NPs with size of 10 nm were decorated on graphene. Au electrode deposited on the graphene showed Ohmic contact and the sensors resistance changed following to various CO2 concentrations. Resulting in resistance sensor using pure graphene can detect minimum of 100 ppm CO2 concentration at 50oC, whereas Au/graphene can detect minimum 2 ppm CO2 concentration at same at 50oC. Moreover, Au NPs catalyst improved the sensitivity of the graphene based CO2 sensors. The responses of pure graphene and Au/graphene are 0.04 % and 0.24%, respectively, at 50oC with 500 ppm CO2 concentration. The optimum working temperature of CO2 sensors is at 75oC