AACVD Grown WO3 Nanoneedles Decorated With Ag/Ag2O Nanoparticles for Oxygen Measurement in a Humid Environment

A sensitive material consisting of silver/silver oxide decorated WO
₃
was successfully grown in two steps via aerosol-assisted chemical vapor deposition. Morphological, structural, and composition analysis revealed that our method is effective for growing WO
₃
nanoneedles decorated with silver/silver oxide nanoparticles at relatively low temperature (≤375 °C) onto sensor arrays printed on an alumina substrate. The sensors were tested for oxygen under humid environment (relative humidity ~85%) with the concentration ranging between 0% and 20%. Gas sensing results showed a good response to oxygen with optimum temperature which was observed at 400 °C for undecorated WO
₃
and at 350 °C for silver/silver oxide decorated WO
₃
. The addition of silver/silver oxide was found to improve the sensor response by almost 300%, making the sensor a potential alternative to replace an existing Pb-based oxygen sensor.