Gas Sensing Properties of Nano-Tungsten Oxide (WO3) Prepared by a Microwave-Assisted Decomposition

WO3 nanoparticles were synthesized by calcinating the precursor, which was obtained via a microwave-assisted decomposition method. The as-prepared WO3 nanoparticles were characterized with field emission scanning electron microscopy (SEM) and X-ray powder diffraction (XRD). The result revealed that the particle sizes were about 100 nm. Gas sensors based on as-prepared WO3 nanoparticles were fabricated, and their sensing performance were tested for response to ethanol, acetone, NO2, H2S, SO2, and NH3 gases. The gas-sensing mechanism was also briefly introduced. The sensor showed excellent selectivity and high sensitivity toward NO2 at relatively low operating temperature (70 degrees C). These results may provide a possible way for low concentration NO2 detection.