Synthesis and NO2 sensing properties of indium oxide nanorod clusters via a simple solvothermal route

Abstract

In this work, a low-cost and environmentally friendly solvothermal route to the synthesis of indium oxide nanorod clusters was described in the presence of sodium chlorate and urea. The morphologies and structures of the as-prepared samples were characterized by X-ray powder diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and high-resolution transmission electron microscopy (HRTEM). The results clearly revealed that the as-prepared indium oxide was composed of nanorods with a diameter of about 15 nm. The gas sensing properties of the as-prepared indium oxide samples were tested towards various gases. The indium oxide nanorod cluster based sensor showed high response and good selectivity toward NO₂ at an operating temperature of 150 °C, giving a response of about 41 to 500 ppb.