Hysteresis-free nanoplasmonic Pd-Au alloy hydrogen sensors.
The recent market introduction of hydrogen fuel cell cars and the prospect of a hydrogen economy have drastically accelerated the need for safe and accurate detection of hydrogen. In this Letter, we investigate the use of arrays of nanofabricated Pd-Au alloy nanoparticles as plasmonic optical hydrogen sensors. By increasing the amount of Au in the alloy nanoparticles up to 25 atom %, we are able to suppress the hysteresis between hydrogen absorption and desorption, thereby increasing the sensor accuracy to below 5% throughout the investigated 1 mbar to 1 bar hydrogen pressure range. Furthermore, we observe an 8-fold absolute sensitivity enhancement at low hydrogen pressures compared to sensors made of pure Pd, and an improved sensor response time to below one second within the 0-40 mbar pressure range, that is, below the flammability limit, by engineering the nanoparticle size.
†Department of Applied Physics, Chalmers University of Technology, 412 96 Göteborg, Sweden.
Carl
C
Wadell
†Department of Applied Physics, Chalmers University of Technology, 412 96 Göteborg, Sweden.
Ferry Anggoro Ardy
FA
Nugroho
†Department of Applied Physics, Chalmers University of Technology, 412 96 Göteborg, Sweden.
Emil
E
Lidström
‡Center for Electron Nanoscopy, Technical University of Denmark, 2800 Kongens Lyngby, Denmark.
Beniamino
B
Iandolo
‡Center for Electron Nanoscopy, Technical University of Denmark, 2800 Kongens Lyngby, Denmark.
Jakob B
JB
Wagner
†Department of Applied Physics, Chalmers University of Technology, 412 96 Göteborg, Sweden.
Christoph
C
Langhammer
Hydrogen sensing; alloy nanoparticles; localized surface plasmon resonance; palladium; plasmonic sensing