Enhanced organic gas sensor based on Cerium- and Au-doped ZnO nanowires via low temperature one-pot synthesis

This paper presents gas sensors based on zinc oxide (ZnO), Ce-doped ZnO (CZO), and Au-doped CZO nanowires (NWs) for the detection of volatile organic compounds (VOCs). Three NW sensing materials were created via one-pot synthesis at low temperature (100 °C). CZO and Au-doped CZO NWs produced a large number of surface oxygen species, which enhanced the responsiveness of the sensors to all types of VOC. Note however that the ZnO NW sensors lacked sensitivity to isopropyl alcohol (IPA). We theorized that overcoming this issue would require doping ZnO NWs with noble metals or rare-earth elements. In experiments, we demonstrated that doping NWs with Au shifted the selectivity of a CZO NWs sensor from acetone to IPA. This study also proposes sensing mechanisms for three metal-doped ZnO NWs.