Dispersed WO3 nanoparticles with porous nanostructure for ultrafast toluene sensing

The preparation of size-controlled materials has shown remarkable potential with regard to their reinforced sensing performance. Herein, we report a facile solvothermal synthesis of dispersed WO3 nanoparticles with porous nanostructure caused by particle assembly. Various characterizations of the as-obtained samples were analyzed. Furthermore, the gas sensing properties of WO3 samples on volatile organic compounds were investigated. The results reveal that the gas sensors based on synthesized WO3 samples with suitable hexamethylenetetramine (HMT) amount and sintering treatment exhibit the highest response (132.0) towards 100 ppm toluene at the optimal working temperature of 225 °C with fast response/recovery time (2 s/6 s), which is attributed to the porous structure of the sensing film and the high resistance caused by well crystallization and grain boundary among the nanoparticles.