Humidity Sensing Properties of Flower-Like VO2(B) and VO2(M) Nanostructures

VO2(B) nanoflowers were synthesized via hydrothermal method, and VO2(M) nanoflowers were obtained through heat-transformation. Two sensors based on VO2(B) and VO2(M) nanoflowers were fabricated and their humidity characteristics were studied. It was found that these sensors exhibited fast response and recovery, perfect reproducibility and good stability. The VO2(M) type sensor is more sensitive at high RH and can be used for high humidity detection. On the contrary, the VO2(B) type sensor has a higher sensitivity at low RH, and can be used for low humidity detection, which is difficult for humidity sensors based on many other semiconductor oxides.