A passive-chipless LC carbon dioxide sensor with non-contact ZnO/CuO/RGO nanocomposites at room temperature

Metal oxides are one of the hot research directions of sensors. Their low cost, high sensitivity, short response time, short recovery time and other advantages have attracted much attention in the field of gas detection. An RFID carbon dioxide sensor based on ZnO/CuO/RGO nanocomposite layer is proposed, which can respond quickly. The ZnO nano materials we prepared by hydrothermal method are rod materials with high specific surface area, and the nano CuO is petal shaped. The heterojunction formed by the two increases the gas adsorption sites, reduces the activation energy when reacting with carbon dioxide, and is also highly sensitive to carbon dioxide at room temperature. Then we use the reduced graphene oxide to change its physical properties and improve the conductivity of semiconductor materials. The sensor determines the amplitude of carbon dioxide concentrationAt room temperature, the amplitude of the sensor varies from −24.0 dB to −13.0 dB. The sensor can quickly respond to and recover from the carbon dioxide concentration of 500 ppm–1600 ppm, and the recovery time varies from 30s to 60s. Compared with the traditional carbon dioxide sensor which needs higher working temperature, this paper designs a carbon dioxide sensor. This RFID carbon dioxide sensor has good temperature adaptability, reversibility, repeatability, low cost and other characteristics, and can be widely used in fruit and vegetable storage, transportation, agricultural greenhouses, indoor environmental monitoring and other fields.