Flame Spray Pyrolysis Synthesis of WO₃ Sensing Materials: Effects of Flame Parameters on Particle Size Distribution and NO₂ Sensing Performance

Abstract

In this study, the flame spray pyrolysis (FSP) technique was employed to produce WO₃ nanoparticles, which were subsequently used as sensing materials for NO₂ sensors. To enhance the sensing performance, the effects of flame parameters on the particle properties and sensing performances for 150-1200 ppb NO₂ at 125 °C were investigated. The results indicate that WO₃ particles with an average crystal size of about 10-20 nm and a standard deviation of about 3-7.5 nm were generated by controlling the precursor and dispersion oxygen flow rate of FSP. Based on the evaluation of NO₂ sensing performance, WO₃ sensing materials synthesized under the 3/5 flame condition exhibited better sensitivity than sensors made under other flame conditions. In summary, the FSP method and the optimization of flame synthesis parameters could be an effective strategy to prepare the sensing materials with high sensing performance.