Trace PdO and Co-MOF derivative modified SnO2 nanofibers for rapid triethylamine detection with little humidity disturbance

Triethylamine is a significant compound, but it is toxic and flammable. Since the humidity in the environment is constantly changing, it is meaningful to develop a sensor that can detect TEA efficiently and is less disturbed by humidity. Here, Pd nanoparticles with a small particle size (about 4 nm) were prepared by reduction method and dispersed on Co-MOF (ZIF-67). Pd@ZIF-67-derived trace PdO and Co3O4 nanoparticles were evenly decorated on SnO2 nanofibers by electrospinning and calcination. The ratios of PdO to SnO2 in PdO-Co3O4-SnO2 were 0.012 wt% and 0.048 wt%, respectively. The response of the sensor based on 0.012 wt% PdO-Co3O4-SnO2 to 20 ppm TEA was 14 at 240 °C. The response time was 3 s and the lowest concentration actually detected was 1 ppm. The synergistic effects of oxygen vacancy, p-n junction, electron sensitization of PdO and morphology of composite improved sensing performance. In addition, due to the inhibition of hydroxyl poisoning by PdO and the oxidation assisting effect of Co3O4, the composite had excellent humidity resistance.