The structure, morphology, and composition of the samples were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM). The α-Fe2O3 microflowers (MFs) with average diameter of several micrometers are assembled of nanorods which possess average diameter and length of 40 nm and hundred nm, respectively. | TAÏP CHÍ PHAÙT TRIEÅN KH&CN, TAÄP 19, SOÁ K5- 2016 C2H5OH and LPG sensing properties of -Fe2O3 microflowers prepared by hydrothermal route Luong Huu Phuoc * Do Duc Tho Nguyen Dac Dien Vu Xuan Hien Dang Duc Vuong School of Engineering Physics, Hanoi University of Science and Technology, Hanoi, Vietnam (Manuscript Received on December 16th, 2015, Manuscript Revised July 19th, 2016) ABSTRACT The flower-like micron-structure of α-Fe2O3 respectively. The gas sensing properties of α- was synthesized via hydrothermal treatment at Fe2O3 film were tested with ethanol (C2H5OH) and liquefied petroleum gas (LPG) at the 140 C for 24 h using Fe(NO3) and Na2SO4 as the precursors. A thin film constructed by the as-prepared material was created by spin coating technique. The structure, morphology, operating temperatures of 225–400 °C. The sensor response of the α-Fe2O3 film reached highest sensitivity to C2H5OH and LPG at 275 C and composition of the samples were characterized by X-ray diffraction (XRD), field and 350 °C, respectively. The thin film exhibited higher sensitivity and lower working temperature emission scanning electron microscopy (FESEM). The α-Fe2O3 microflowers (MFs) with to C2H5OH than those to LPG. The film can detect minimum concentration of 250 ppm average diameter of several micrometers are C2H5OH. The response time of the film to assembled of nanorods which possess average diameter and length of 40 nm and hundred nm, C2H5OH is approximately 30 s. Keywords: α-Fe2O3, gas sensor, microflower, nanorod, hydrothermal. 1. INTRODUCTION Hematite (α-Fe2O3) is the most stable iron oxide under ambient conditions which behaves as an n-type semiconducting material with band gap of eV [1]. It is frequently applied as semiconducting material, dielectric material, magnetic material, sensitive material and catalyst, etc. [2-6]. In recent years, much effort has been focused on the fabrication of nanostructure materials with a .
