Shape-controlled synthesis of palladium and copper superlattice nanowires for high-stability hydrogen sensors.
For hydrogen sensors built with pure Pd nanowires, the instabilities causing baseline drifting and temperature-driven sensing behavior are limiting factors when working within a wide temperature range. To enhance the material stability, we have developed superlattice-structured palladium and copper nanowires (PdCu NWs) with random-gapped, screw-threaded, and spiral shapes achieved by wet-chemical approaches. The microstructure of the PdCu NWs reveals novel superlattices composed of lattice groups structured by four-atomic layers of alternating Pd and Cu. Sensors built with these modified NWs show significantly reduced baseline drifting and lower critical temperature (259.4 K and 261 K depending on the PdCu structure) for the reverse sensing behavior than those with pure Pd NWs (287 K). Moreover, the response and recovery times of the PdCu NWs sensor were of ~9 and ~7 times faster than for Pd NWs sensors, respectively.
Department of Physics, University of Puerto Rico at Rio Piedras San Juan, PR 00931, USA.
Dachi
D
Yang
Department of Physics, University of Puerto Rico at Rio Piedras San Juan, PR 00931, USA.
Jennifer
J
Carpena-Núñez
Department of Physics, University of Puerto Rico at Rio Piedras San Juan, PR 00931, USA.
Luis F
LF
Fonseca
NASA Glenn Research Center, Cleveland, OH 44135, USA.
Azlin
A
Biaggi-Labiosa
NASA Glenn Research Center, Cleveland, OH 44135, USA.
Gary W
GW
Hunter
D003300:Copper / Q000737:chemistry; D006859:Hydrogen / Q000737:chemistry / Q000302:isolation & purification*; D053770:Nanowires / Q000737:chemistry*; D010165:Palladium / Q000737:chemistry
D010165:Palladium; D003300:Copper; D006859:Hydrogen