Hydrothermal Synthesis of Fe2O3 for the Humidity Sensing Application

Abstract

Fe2O3 nanorods have been successfully synthesized by a hydrothermal method using a stainless steel Teflon autoclave. The solution of FeCl3 and urea was transferred to a Teflon-lined stainless-steel autoclave and then maintained at a temperature of 180°C for 24 hours. The prepared Fe2O3 powder was characterized by X-ray Diffraction (XRD), and the result shows the formation of the Hematite phase of Fe2O3 after calcination at 400°C for 2 hours. Field Emission Scanning Electron Microscopy (FESEM) was used to study the morphology of synthesized Fe2O3 powder, and the result indicates that a bunch of nanorods was formed with a width of 44 nm and a length of 220 nm. Also, Fourier Transform Infrared spectroscopy (FTIR) and X-ray Photoelectron Spectroscopy (XPS) techniques were used to characterize synthesized Fe2O3 nanorods. To study the humidity sensing performance of Fe2O3 nanorods, a sensor was synthesized as an interdigitated electrode coated with sensing material on top of the electrode. The present study investigated the good humidity sensing performance of Fe2O3 nanorods at room temperature in a humidity (RH) range of 11%-97% at DC condition.