Conductometric NO2 gas sensors based on MOF-derived porous ZnO nanoparticles

Abstract

As a typical metal oxide semiconductor, ZnO has been investigated deeply for the application of gas sensing materials. In this study, an ultrahigh sensitive and selective NO2 gas sensor based on porous ZnO nanocubes derived from metal organic frameworks (MOFs) was reported. The MOF-derivatives were obtained by precisely control of the subsequent pyrolysis process. The sensitivity of MOF-derivatives toward 1 ppm NO2 at 200 ºC was 51.41 under 500 ºC pyrolysis treatment. Compared with similar work, the sensitivity has been greatly improved. Furthermore, the fabricated gas sensor demonstrated excellent selectivity to NO2 over other gases (CO, C2H5OH, H2, H2S, NO, NH3). The ultrahigh sensitivity and selectivity were attributed to the unique structure after pyrolysis, which provides more exposed active sites and connected pore channels.