Synthesis of mesoporous α-Fe2O3 nanostructures via nanocasting using MCM-41 and KIT-6 as hard templates for sensing volatile organic compounds (VOCs)

The work describes the synthesis of mesoporous alpha-Fe2O3 using two different forms of mesoporous silica MCM-41 and KIT-6 as hard templates employing nanocasting technique. The structural features of fabricated mesoporous alpha-Fe2O3 were studied using small angle X-ray scattering, X-ray diffraction and Fourier transform infrared spectroscopy. Surface properties of the oxides with porous morphology were studied by N-2 sorption isotherms and Brunauer-Emmett-Teller studies, scanning electron microscopy and transmission electron microscopy. The mesoporous alpha-Fe2O3 oxides were then tested for detection of volatile organic compounds namely acetic acid, ethanol and formaldehyde. The alpha-Fe2O3 prepared from KIT-6 shows sensitivity of 45.21 towards acetic acid at temperature of 110 degrees C, much lower as compared to the temperatures reported in literature with short response and recovery times. The sensitivity obtained for acetic acid is over eight times higher than that for ethanol and formaldehyde making it a potentially selective sensor for acetic acid detection.