Hydrogen sensing properties and mechanism of NiO-Nb2O5 composite nanoparticle-based electrical gas sensors

A simple hydrothermal method was used to prepare NiO-Nb2O5 composite nanoparticle electrical sensors for the detection of hydrogen (H2) at room temperature. To investigate the morphology and crystal structure of the synthesized powders, the synthesized nanoparticles were characterized by scanning electron microscopy and X-ray diffraction. The NiO-Nb2O5 composite nanoparticle sensor showed stronger and faster response to H2 than the pristine Nb2O5 one at room temperature. Only weak responses were observed to carbon monoxide, methane and ethanol, indicating that the NiO-Nb2O5 composite nanoparticle sensor could be a potential candidate as a practical gas detector. In this study, the H2 sensing properties and mechanism of NiO-Nb2O5 composite nanoparticle-based electrical gas sensors are discussed in detail.