A novel method for improving the performance of ZnO gas sensors

A novel ZnO porous nanosolid has been prepared by hydrothermal hot-press method, and the measurements indicated that it had very uniform pore size. Compared with the sensor fabricated from conventional ZnO nanoparticles (denoted as S-1), the sensor from ZnO porous nanosolid (denoted as S-2) showed much better sensing performance towards several organic vapors; the intrinsic resistance of S-2 in air dramatically decreased and its selectivity was improved. The optimum working temperature of S-2 was 370 °C, whereas that of S-1 was as high as 420 °C. The differences in gas sensing performance between the two kinds of sensors were analyzed based on the scanning electron microscopy (SEM) and high resolution transmission electron microscopy (HRTEM) measurements.