A room temperature oxygen gas sensor based on hierarchical TiO2

Three-dimensional TiO
₂
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 TiO
₂
shaped like dandelion are synthesized by hydrothermal process. The dandelion-like nanostructured TiO
₂
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% O
₂
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 TiO
₂
could be a promising sensing material for O
₂
detection at room temperature.