Micro-wrinkled palladium surface for hydrogen sensing and switched detection of lower flammability limit

F. Greco, L. Ventrelli, P. Dario, B. Mazzolai, V. Mattoli

Research output: Contribution to journalArticle

21 Citations (Scopus)

Abstract

We report the development and testing of a novel hydrogen sensor that shows a very peculiar response to hydrogen exposure, due to its micro-structured palladium surface. The fabrication of the wrinkled Pd surface is obtained using an innovative, fast and cheap technique based on the deposition of a thin Pd film on to a thermo-retractable polystyrene sheet that shrinks to 40% of its original size when heated. The buckling of the Pd surface induced by shrinking of the substrate produces nano and micro-wrinkles on the sensor surface. The micro-structured sensor surface is very stable even after repeated hydrogen sorption/desorption cycles. The hydrogen sensing mechanism is based on the transitory absorption of hydrogen atoms into the Pd layer, leading to the reversible change of its electrical resistance. Interestingly, depending on hydrogen concentration the proposed sensor shows the concurrent effect of both the usually described behaviors of increase or decrease of resistance, related to different phenomena occurring upon hydrogen exposure and formation of palladium hydride. The study reports and discusses evidences for an activation threshold of hydrogen concentration in air switching the behavior of sensor performances from, e.g., poor negative to large positive sensitivity and from slow to fast detection.

Original languageEnglish
Pages (from-to)17529-17539
Number of pages11
JournalInternational Journal of Hydrogen Energy
Volume37
Issue number22
DOIs
Publication statusPublished - 2012 Nov
Externally publishedYes

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Keywords

  • Hydrogen sensor
  • Lower flammability limit
  • Micro-structured surface
  • Palladium film

ASJC Scopus subject areas

  • Renewable Energy, Sustainability and the Environment
  • Fuel Technology
  • Condensed Matter Physics
  • Energy Engineering and Power Technology

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