Abstract:
Diethylamine vapor is harmful to people if inhaled or swallowed, as it results in the oxidation of hemoglobin in
the body into unwanted methemoglobin, which is unable to transport oxygen in the blood, resulting in reduced
blood oxygenation. Lack of blood oxygenation leads to hypoxemia. MnO2 nanorods, carbon soot, and
MnO2@ZIF-8 are sensing materials used to prepare solid-state gas sensors that operate at room temperature. The
prepared sensing materials were characterized by scanning electron microscopy, transmission electron microscopy, powder X-ray diffraction, X-ray photoelectron spectroscopy, and Fourier-transform infrared spectroscopy.
The performance of the MnO2@ZIF-8 based sensor improved significantly when the carbon soot was introduced
into the composite. The effect of the amount of CNPs in the composite on the performance of the sensors was
studied. The MnO2@ZIF-8/CNPs-based sensor with a 3:1 mass ratio was highly selective towards diethylamine
vapor over acetone, methanol, ethanol, and 3-pentanone vapors. An in situ FTIR coupled with LCR meter was
used to understand the sensing mechanism of diethylamine vapor and it was found that the sensing mechanism
was by deep oxidation of diethylamine to CO2, H2O, and other molecules. The sensing mechanism was studied by
monitored by CO2 band intensity which was produced from the reaction between the sensing materials and the
analyte vapor. As the sensor’s exposure time increased the intensity of the CO2 IR band increased. We observed
the direct relationship between the surface reaction rate and the sensor’s sensitivity.
