Single CeO2 nanowire gas sensor supported with Pt nanocrystals:: Gas sensitivity, surface bond states, and chemical mechanism

We present a new type of CeO2 nanodevice in which a single CeO2 nanowire was used as the sensing unit. It was found that incorporation of Pt nanocrystals on CeO2 nanowire could significantly increase the sensor response. A possible mechanism was discussed based on the study of morphology and surface bond states of the nanowire using local electron energy loss spectroscopy and X-ray photoemission spectroscopy. The results provide a pathway to improve the performance of gas sensors with a good understanding of the nanowire's surface physics and chemistry.