Yang Dachi, Carpena-Núñez Jennifer, Fonseca Luis F, Biaggi-Labiosa Azlin, Hunter Gary W
Department of Physics, University of Puerto Rico at Rio Piedras San Juan, PR 00931, USA.
NASA Glenn Research Center, Cleveland, OH 44135, USA.
Sci Rep. 2014 Jan 20;4:3773. doi: 10.1038/srep03773.
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.
对于采用纯钯纳米线制造的氢传感器，在较宽温度范围内工作时，导致基线漂移和温度驱动传感行为的不稳定性是限制因素。为了提高材料稳定性，我们通过湿化学方法制备了具有随机间隙、螺纹和螺旋形状的超晶格结构钯铜纳米线（PdCu NWs）。PdCu NWs的微观结构揭示了由交替排列的钯和铜的四原子层构成的晶格群组成的新型超晶格。用这些改性纳米线制造的传感器显示出基线漂移显著降低，并且与纯钯纳米线传感器相比，反向传感行为的临界温度更低（根据PdCu结构，分别为259.4 K和261 K）（纯钯纳米线为287 K）。此外，PdCu NWs传感器的响应时间和恢复时间分别比钯纳米线传感器快约9倍和约7倍。
