A superior sensor consisting of porous, Pd nanoparticle–decorated SnO2 nanotubes for the detection of ppb-level hydrogen gas

•Pd decorated porous SnO2 nanotubes are synthesized.•Ppb-scale H2 gas sensing performances are analyzed.•Effect of structure of the nanomaterials in H2 sensing is analyzed.•Enhanced sensing mechanisms of the sensor are discussed. Pd nanoparticle–decorated SnO2 nanotubes (Pd/SnO2 NTs) are synthesized in this study by electrospinning (using a coaxial spinneret) for application as a hydrogen gas sensor. The inner and outer diameters of the porous, polycrystalline Pd/SnO2 NTs are 80 nm and 120 nm, respectively, and the Pd nanoparticles decorating the Pd/SnO2 NTs are comparatively small with an average diameter of 5 nm. The catalytic effect of the Pd nanoparticles and the large effective surface area of the Pd/SnO2 NTs enhance the performance of a resulting sensor. Furthermore, owing to the hollow, porous, polycrystalline structures of the SnO2 nanotubes, Pd nanoparticles decorate with high loading and uniform distribution of each constituent grain, maximizing their catalytic effect. As a result, the sensing response of a Pd/SnO2 NT sensor to 10 ppm hydrogen gas of 54.43 is 4.3 times higher than that of a SnO2 NT sensor of 12.69.