WO3-based NO2 sensors fabricated through low frequency AC electrophoretic deposition

Mesoporous tungsten oxide was synthesized based on hard template method using silica as template. The produced material was investigated structurally using X-ray diffraction and high resolution TEM. The material was deposited on patterned alumina substrates through low frequency AC electrophoresis of which, the deposition pattern was studied using optical microscopy and SEM. Exposure of the sensors to NO2 in the temperature range of 150–300 °C resulted in highest sensitivity at 200 °C. Increasing temperature was found to produce faster response and recovery processes while the sensitivity decreased.