Fundamentals and Classifications of CO2 Sensors

Sensors that detect CO2 gas have a significant potential market, as they are utilized in a variety of industries, including food packaging, indoor air quality testing, and monitoring of CO2 emissions in efforts to mitigate global warming. These sensors play a critical role in environmental monitoring, chemical safety control, and various industrial applications. However, detecting CO2 with accuracy and reliability is a challenging task due to the wide range of CO2 concentrations to be measured. Given the diverse range of applications for CO2 gas sensors, it is crucial to develop new materials and approaches that can operate effectively under varying conditions. Nanomaterial-based metal oxides, carbon-based materials, and 2D transition metal dichalcogenides have shown great potential for use in CO2 sensing. Such materials offer unique advantages in terms of selectivity, sensitivity, response time, and detection capabilities. This chapter discusses the different sensing techniques, the future trends in nanomaterial-based CO2 sensors, and their limitations. The correlation between the compositing structures and their CO2 sensing properties and the challenges and outlooks of chemo-resistive CO2 gas sensors will be discussed. Overall, the use of nanomaterials in CO2 sensing presents opportunities for reliable and inexpensive CO2 sensors with high performance.