BTEX Gas Sensor Based on Hematite Microrhombuses

Over the past fifty years, gas sensors based on metal semiconducting oxides (MOXs) have drawn attention due to their performance in detecting various gases. Thus, we report herein on a BTEX gases sensor based on hematite (alpha-Fe2O3) microrhombuses synthesized via the hydrothermal method. X-ray diffraction and X-ray absorption spectroscopy analyses indicated the presence of a pristine hematite phase after hydrothermal treatment. Electron microscopy analyses revealed that the hematite sample consists of single-crystals with a rhombus-like shape and an average size of 140 nm. Electrical measurements pointed out that hematite microrhombuses were sensitive towards sub-ppm BTEX levels, in which the minimum detected level was 3 ppb and the long-term stability was 1 month. The results presented here demonstrate the potential of hematite microrhombuses as a sensing material to manufacture BTEX gas sensor devices.