Fullerene-decorated PdCo nano-resistor network hydrogen sensors with sub-second response and parts-per-billion detection at room temperature.

Ngo, Tu Anh; Magar, Ashwin T; Pham, Minh T; Luong, Hoang M; Phan, Thi Thu Trinh; Trinh, M Tuan; Jung, Michael; Larsen, George K et al. · Nat Commun · 2025

basic_science · Level V

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Abstract

Hydrogen detection with rapid response and ultra-low detection limits remains a critical challenge for safety and energy applications. Here, we report a fullerene-decorated PdCo nano-resistor network sensor that integrates nanostructuring, alloying, and surface-engineering approaches. The C<sub>60</sub> layer enhances sensor performance by increasing the surface-to-volume ratio, enabling fast hydrogen diffusion, relieving mechanical stress during cycling, and guiding nanostructure morphology. Our composite device (20 nm C<sub>60</sub>/3 nm Teflon AF/5 nm Pd<sub>63</sub>Co<sub>37</sub>/30 nm Teflon AF) achieves a response time of 0.40 ± 0.06 s across 1-100 mbar H<sub>2</sub> and detects 40 ppb H<sub>2</sub> with a signal-to-noise ratio of 10 at room temperature. A poly(methyl methacrylate) (PMMA) topcoat further improves cycling stability and selectivity under 90% relative humidity and interfering gases. This design provides a scalable approach and opens the door to future adaptation of porous carbon-based frameworks and polymeric interlayers to realize robust, high-performance hydrogen sensors for real-world applications.