文章信息

In this research, a semiconductor metal oxide (SMO)-based gas sensor was designed for the ultrasensitive and  tunably selective detection of formaldehyde and acetone. Cobalt-doped 3D inverse opal SnO2 multilayer films  (3D IO Co-SnO2 MFs) used as sensing materials were prepared with the ultrasonic nebulizing deposition (UND)  method combined with a self-assembly template. The 3D IO Co-SnO2 (Co/Sn = 1:24 atom%) MF-based sensor  exhibited a much higher response and lower limit of detection to the volatile organic compounds (VOC) gases  because of the larger specific surface area, effective gas accessibility, high catalytic activity, and increased  chemisorbed oxygen species generated by the elevation of the Fermi level and the narrowing of the band gap.  More importantly, the 3D IO Co-SnO2 MF-based sensor showed dual-model gas sensing characteristics for  selectively detecting formaldehyde and acetone at 200 ◦C and 225 ◦C, respectively, because of the difference of  the VOC catalytic conversion and surface oxidative reaction rate that was dependent on the operating  temperature.