A review of nanostructured carbon dioxide sensors based on electrical and thermal conductivity
Firouzeh Salimian, Alireza Hemmati, Ahad Ghaemi
Abstract
• This review focuses on new approaches of several types of technologies for synthesizing carbon dioxide sensors using conductometry. • Researchers have discussed ways to improve measurement performance, such as selectivity, sensitivity, response time, and recovery time, using different materials and catalysts. • The use of conductive sensors has increased due to their unique advantages, such as their wide detection range of 10 to 1000 ppm, long lifetime, and short response time for CO 2 detection. • If accuracy and fast response are considered, thermal conductivity sensors are better options. • Regarding cost and compatibility with electronic systems, electrical sensors also have great potential. This review focuses on new approaches of several types of technologies for synthesizing carbon dioxide sensors using conductometry. Researchers have discussed ways to improve measurement performance using different materials and catalysts, such as selectivity, sensitivity, response, and recovery time. From 2020 onwards, conductive sensors have increased due to their unique advantages, such as a wide detection range of 10 to 1000 ppm, long lifetime, and short response time for CO 2 detection. reliable and quantitative detection of CO₂ requires diverse material strategies capable of operating under various environmental conditions. In general, there are two types of conductive sensors: thermal and electrical conductive sensors with different specifications and can be chosen to suit specific applications, environments and budgets. If accuracy and fast response are considered, thermal conductive sensors are better options. However, in terms of cost and compatibility with electronic systems, electrical sensors also have great potential. This review discusses the types of nanomaterials used for CO 2 gas detection sensors, including metal oxide-based nanomaterials, polymer nanomaterials, carbon nanomaterials, and various nanocomposites. This review examines nanocomposites' electrical and thermal conductivity properties, how they are affected by adding specific nanoparticles, and how to control the composite's performance characteristics, such as thermal and electrical conductivity, by selecting appropriate nanoparticle fillers. Nanomaterials used in CO 2 sensing enable reliable and inexpensive sensors with high performance. Research has proven that semiconducting metal oxides exhibit high conductivity at high temperatures of 600 ºC.