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 (H2) 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 H2 responses with different gas concentrations. The 4 nm thick sensor showed the highest response (ΔR/R0) to H2 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 H2 selectivity against other interfering gases. The H-PdNTN H2 sensor provides a facile and cost-effective way to fabricate high-performance H2 sensors.