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.