Revealing the relationship between Au decoration method and enhanced acetone sensing performance of mesoporous In2O3-based gas sensor
In this study, long-term ordered mesoporous In2O3 was prepared by replicating the structure of SBA-15, samples prepared with Au-doped and Au-loaded were aimed at studying the influence of modification method (doping and loading) on acetone sensing properties. And the corresponding sensing mechanism has been discussed in details. Structural and chemical characterizations of samples have been carried out by XRD, BET, TEM and XPS. The best sensing performance has been achieved in In2O3 Au-doped (IO-Au-D) sample, the response reaches 19.01 to 100 ppm of acetone at 250 oC. The effects of polarity and band dissociation energy of acetone benefited the improved selectivity among volatile organic compounds (VOCs). The excellent gas sensing performance not only depended on the ordered mesoporous structure of In2O3 matrix, but also attributed to the “electronic sensitization” and “chemical sensitization” of Au. Furthermore, uniformly dispersed Au-doped depressed the lattice growth and enlarged the depletion region played a great role in enhancing sensing performance. However, the limited surface decorated region of Au-loaded sample suppressed the enhancement of acetone sensing performance. This work significantly revealed that the sensing performance could be controlled by different introducing additives methods.