A room temperature oxygen gas sensor based on hierarchical TiO2

Abstract

Three-dimensional TiO2 with nanoscale structures, such as porous films, porous spheres, and hierarchical structures, play a promising role in the fields of gas sensors. In this work, hierarchical TiO2 shaped like dandelion are synthesized by hydrothermal process. The dandelion-like nanostructured TiO2 is analyzed by X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). Then the study focus on the gas sensing properties for oxygen at room temperature. It is found that the hierarchical TiO2 have a reversible sensing capacity to 1% O2 at room temperature with response time and recovery time less than 50 seconds and 60 seconds, respectively. At room temperature of 25±1C, resistance changes of the sensor were dependent on O2 gas concentrations. It is suggested that the hierarchical TiO2 could be a promising sensing material for O2 detection at room temperature.