Trimethylamine gas sensor based on bimetallic Ag/Cu@CuFe2O4: Experiment and DFT calculation

In this study, Ag/Cu@CuFe₂O₄ nanocomposites were prepared using hydrothermal method and sedimentation-precipitation method for the detection of TMA gas. The morphology, crystal structure and elemental composition of the materials were analyzed by XRD, SEM, EDS and XPS characterization, and the results showed that the Ag/Cu@CuFe₂O₄ composites were successfully synthesized. When the content of Ag was 10% by molar ratio, the Ag/Cu@CuFe₂O₄ (ACF-10) sensor exhibited optimal performance at a working temperature of 150 ^oC, showing the best response to TMA gas. The ACF-10 sensor had a response and recovery time of 8 s and 14 s for 20 ppm TMA, with a response value of 42.8%. The sensor also demonstrated excellent selectivity, repeatability, and enduring stability over the long-term. The presence of Ag and Cu increases the adsorption of TMA gas on the material's surface by promoting catalytic reactions with oxygen molecules. Additionally, the enhanced TMA gas sensing performance of the Ag/Cu@CuFe₂O₄ nanocomposite material was further elucidated through theoretical calculations based on first principles. The constructed TMA gas detection circuit can detect and display TMA gas concentration, enabling real-time TMA gas detection functionality.