Hydrothermal Synthesis of CNTs/Co3O4@rGO Mesopours Nanocomposite as a Room Temperature Gas Sensor for VOCs

In the present paper, the effect of reduced graphene oxide (rGO) and carbon nanotubes (CNTs) on the gas-sensing properties of Co3O4 has been reported. The Co3O4/CNTs@rGO composite was synthesized using hydrothermal method. Samples were characterized by high resolution transmission electron microscope, Raman spectroscopy, Fourier transform infrared spectroscopy, differential thermal analysis, thermogravimetric analysis, Brunauer-Emmett-Teller surface area, and Barrett-Joyner-Halenda pore size measurements. The X-ray diffraction measurements confirmed the formation of the Co3O4 spinel structure. The Co3O4/CNTs@rGO exhibited mesoporous structure and high specific surface area of 92.9 m(2)/g. The gas-sensing properties of the synthesized composite are evaluated toward volatile organic compounds (VOCs). The gas-sensing tests revealed that the prepared composite showed a remarkable response to ethanol at room temperature compared to other volatile organic compounds with fast response time. Due to the intriguing merits characteristics, Co3O4/CNTs@rGO composite could achieve remarkable sensitivity to VOCs especially ethanol, demonstrating great potential in next-generation room-temperature gas sensor based on P-type semiconductor.