Room temperature hydrogen sensing properties of multiple-networked Nb2O5-nanorod sensors decorated with Pd nanoparticles

Nb 2 O 5 nanosensors showing good sensing performances toward hydrogen and oxygen at high temperatures have been reported several times, but high-performance room-temperature Nb 2 O 5 gas sensors have not been reported to date. Pd-Nb 2 O 5 nanorods were synthesized by using thermal oxidation of a Nb foil, followed by wet chemical coating of Pd under UV illumination. The responses of multiple-networked Pd-Nb 2 O 5 nanorod sensors to 10,000 ppm of hydrogen at room temperature were ∼218% and ∼496%, respectively. Responses obtained in this study were far higher than that to 2,000 ppm of H 2 obtained previously at the same temperature by using Pt/Nb 2 O 5 Schottky-diode sensors. These results suggest that multiple-networked 1D nanostructure sensors, which can be fabricated more easily, are superior in H 2 -gas-sensing properties to Schottky-diode-type nanostructure sensors, which require precise techniques to connect the nanostructures. The origin of the enhanced sensing properties of the Pd-decorated Nb 2 O 5 nanorods toward hydrogen is also discussed.