Pt-doped α-Fe2O3 mesoporous microspheres with low-temperature ultra-sensitive properties for gas sensors in diabetes detection

In this study, Pt-doped alpha-Fe2O3 mesoporous microspheres were prepared by a simple solvothermal method and used for the detection of acetone. XRD, SEM, TEM, Raman, FT-IR, XPS, UV-vis and O2-TPD were utilized to characterize the structure and chemical properties of the samples. Different components were prepared by controlling the amount of the amount of Pt, and the corresponding sensing performance detection was carried out. The excellent sensing performance was obtained in the sample of 2 at% Pt-doped alpha-Fe2O3 (Pt2%-Fe). At a lower operating temperature (175 degrees C), the Pt2%-Fe sensor response of 100 ppm acetone reaches 105, which is 2.5 times of pure alpha-Fe2O3. Even the concentration reduces to 20 ppb acetone, the response can still reach 1.24 at 175 degrees C. Meanwhile, the favorable sensing performance can still be maintained under high humidity (90 % RH). The addition of Pt increases the specific surface area and reduces the band gap of the sensitive material. The excellent acetone sensing performance indicated that doping Pt effectively increases the adsorption capacity (catalytic properties) of the surface for the sensitive material and the sensitivity to the target gas (alter in the depletion layer). Hence, this high response, low detection limit and good moisture resistance sensor has a sig-nificant potential in the detection of acetone in human breath.