Half-Pipe Palladium Nanotube-Based Hydrogen Sensor Using a Suspended Nanofiber Scaffold.

A half-pipe palladium nanotube network (H-PdNTN) structure was developed for high-performance hydrogen (H) sensor applications. To fabricate the sensor, suspended poly(vinyl alcohol) (PVA) nanofiber bundles were electrospun on a conductive substrate, followed by a palladium (Pd) deposition on top of the PVA nanofiber bundles. Then, Pd-deposited PVA nanofibers were transferred to a host substrate, and the PVA nanofiber templates were selectively removed. Various material analyses confirmed that the PVA nanofibers were successfully dissolved leaving a half-pipe-shaped Pd nanotube network. The fabricated Pd nanotube-based sensors were tested for H responses with different gas concentrations. The 4 nm thick sensor showed the highest response (Δ R/ R) to H gas. Platinum (Pt) decoration of the sensor showed an improved response speed compared to that of the pristine sensor via the catalytic function of Pt. Additionally, the sensor exhibited good H selectivity against other interfering gases. The H-PdNTN H sensor provides a facile and cost-effective way to fabricate high-performance H sensors.