Niobium oxide 2 Orthorhombic phase Anodic oxidation 1 Anodization 1 Anodization voltages 1 Anodizations 1 Catalytic layers 1 Chemical detection 1 Chemical sensors 1 Current voltage characteristics 1 Different voltages 1 Electronic equipment 1 Energy gap 1 Gas detectors 1 Gas sensing electrodes 1 Gas sensing properties 1 Gas sensor 1 Gases 1 Hydrogen gas sensing 1 Hydrogen gas sensors 1 IV characteristics 1 Light illumination 1 Mesoporous materials 1 Metal testing 1 Nano-porous 1 Nanoporous 1 Nanoporous structures 1 Niobium 1 Oxide films 1 Platinum 1