CO2 sensing at ambient conditions using metal-organic frameworks

Determining accurately the CO2 levels is highly relevant when monitoring the indoor air quality. Nondispersive Infrared (NDIR) sensors are the most often used for measuring carbon dioxide concentration. However, the complexity of the device, the power consumption as well as scalability are the main drawbacks associated with the state-of-the-art devices. In this work, we discuss the application of metal-organic framework for sensing of CO2 molecules using electrochemical impedance spectroscopy. Impedance CO2 sensors were fabricated using two metal-organic frameworks known for their selective CO2 adsorption capability as well as their high proton conductivity , namely Zn-MOF-74 and NdMo-MOF. Both sensors showed significant change of the impedance by changing the CO2 concentration and the relative humidity. Notably, Zn-MOF-74 impedance sensor showed fast response by changing the humidity and CO2 concentration.