Synthesis of VO2 thin films from vanadium powder and determination of room-temperature NH3 sensing properties

VO 2 nanomaterials were synthesized directly from vanadium powder and NH 4 OH solution. The effect of annealing temperature on the formation of VO 2 and V 2 O 5 phases of materials after synthesis was investigated and analyzed. The material is composed of nanoparticles with an average size of about 2 nm. The gas sensing properties of VO 2 samples at room temperature were studied. The VO 2 nanomaterial was selective toward NH 3 at 25 °C among other test gases such as C 2 H 5 OH, CH 3 COCH 3 , and C 3 H 8 . The effects of moisture, stability, and gas-sensing mechanism of VO 2 nanomaterials were also investigated and discussed. VO 2 nanomaterials have simple fabrication and superior air sensitivity and thus have great potential as NH 3 sensors at room temperature.