Low-cost and high-stable C-SiO2-PTFE gas diffusion membrane for ultrafast electrochemical NO2 sensor

Electrochemical gas sensors (EGSs) are the most effective means for detecting NO 2 gas in industry, while facing the issue of exorbitant cost due to the use of expensive Pt catalyst. Herein, well-dispersed C-SiO 2 into polytetrafluoroethylene (PTFE) was adopt as high-stable gas diffusion membrane for ultrafast electrochemical NO 2 sensors. The nano-SiO 2 not only prevents material aggregation but also constructs porous networks between the gas diffusion electrode and gas molecules, providing a larger sensing area for high sensor performance. The fabricated sensor exhibits excellent response linearity, short response time, and high stability. As compared with commercial Pt/C electrode, the sensor response is improved by 170 %. Moreover, a multiple linear regression model was introduced to predict the response values of NO 2 in the range of 5–100 ppm, achieving only 1.5 % deviation from the real values. This work not only demonstrates the feasibility of non-precious metals in gas diffusion membranes but also provides guide for designing next-generation low-cost EGSs.