Room temperature CO2 detection by metal oxides based nanosensors

Carbon dioxide is considered a greenhouse gas and is the main cause of global warming. CO₂ emissions are increasing each year (420 ppm this year). Therefore, it is important to be able to detect these CO₂ levels with sensors that can work at room temperature (RT). An array of 4 sensors (Fe₂O₃, SnO₂, ZnO and CuO) has been tested for the detection of CO₂ at RT in dry and humid (50 %HR) air. Low-cost sensors were prepared by the drop-casting technique from nanoparticle dispersions. Photoactivation of the sensors with UV-LED allows detection of CO₂ at ambient temperature. Humidity improves the response of all sensors to CO₂ and concentrations as low as 100 ppm CO₂ can be detected.