Boosting the sensitivity and stability of microwave gas sensor for acetone detection based on SnO2/Co3O4 nanofibers and micro-heater

Traditional microwave gas sensors have been widely used for gas detection at room temperature due to the advantages of high sensitivity and multi-parameter detection. However, the detection results can be significantly affected by the change of humidity, which restricts their application in practical environments. To solve this problem, a microwave gas sensor based on SnO 2 /Co 3 O 4 composite nanofibers, a micro-heater and a dual-mode resonator was proposed, achieving high-precision measurement of acetone within the range of 10~500 ppm. The integration of micro-heater can reduce water molecule adsorption, leading to enhanced sensing stability under varying humidity levels. The results demonstrate that the construction of SnO 2 /Co 3 O 4 heterostructures can enhance the sensitivity due to increasing charge transfer capability. The maximum sensitivity reached 3.938 mdB/ppm at the optimal operating temperature of 150 ℃, which is approximately five times higher than that of room temperature conditions. Moreover, the sensitivity of the microwave gas sensor maintains almost unchanged under different humidity, which can be attributed to the integration of micro-heater. This work provides a novel strategy for the design of microwave gas sensors in practical environments.