Selective hydrogen sensor for liquefied petroleum gas steam reforming fuel cell systems

Nowadays miniaturized sensors have become more and more important in order to monitor several fields of urban ambient and human life carefully. Low cost synthesis of nanostructured metal oxides for gas-sensing application is therefore of crucial importance for a mass production. Herein, NiO nanostructures were grown and used to realize sensors selective to hydrogen gas in presence of liquefied petroleum gas (LPG), to be used on portable and isolated fuel cell systems. NiO p-type semiconducting nanowires with polycrystalline structure were prepared via an easy, cheap and scalable hydrothermal method. Morphology and crystal structure of the NiO nanowires were characterized by scan electron microscopy, X-ray diffraction, transmission electron microscopy and selected area electron diffraction. The nanostructured material was then tested as hydrogen sensor showing very good performance in terms of sensor response (110%), stability, speed of response and recovery (20 s) and selectivity in presence of LPG (a ratio of 200 times).