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Galvanically Displaced Ultralong PbxSeyNiz Hollow Nanofibers with High Thermopower
journal contribution
posted on 2014-04-22, 00:00 authored by Miluo Zhang, Jiwon Kim, Seil Kim, Hosik Park, Hyunsung Jung, N. George Ndifor-Angwafor, Jaehong Lim, Yongho Choa, Nosang V. MyungA cost-effective
process that combines electrospinning and a galvanic
displacement reaction was utilized to synthesize ultralong hollow
PbxSeyNiz nanofibers with controlled dimensions, morphology,
composition, and crystal structure. Ni nanofibers were electrospun
with an average diameter of 150 nm and were used as the sacrificial
material for the galvanic displacement reaction. The composition and
morphology of the PbxSeyNiz nanofibers were controlled
during the reaction by tuning the concentration of HSeO2+ in the electrolytes. Hollow PbxSeyNiz nanofibers with smooth surfaces were obtained from the low-concentration
HSeO2+ solution (i.e., 0.01 and 0.05 mM), but
the hollow nanofibers synthesized from the high-concentration HSeO2+ solution (i.e., 1 mM) have rough outer surfaces
with nanocrystal protrusions. The Pb content of the nanofibers’
composition was varied from 3 to 42% by adjusting the HSeO2+ concentration. The thermoelectric properties of the
nanofiber mats were characterized, and the highest Seebeck coefficient
of approximately 449 μV/K at 300 K was found for the Pb37Se59Ni4 nanofiber mat.