Synthesis of Mn-doped CeO2 nanorods and their application as humidity sensors

Mn-doped CeO2 nanorods have been prepared from CeO2 particles through a facile composite-hydroxide-mediated (CHM) approach. The products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The analysis from the X-ray photoelectron spectroscopy indicates that the manganese doped in CeO2 exists as Mn4 + . The responses to humidity for static and dynamic testing proved doping Mn into CeO2 can improve the humidity sensitivity. For the sample with Mn% about 1·22, the resistance changes from 375·3 to 2·7MΩ as the relative humidity (RH) increases from 25 to 90%, indicating promising applications of the Mn-doped CeO2 nanorods in environmental monitoring.