TY - JOUR
T1 - Beyond Archimedean solids
T2 - Star polyhedral gold nanocrystals
AU - Burt, Justin L.
AU - Elechiguerra, Jose L.
AU - Reyes-Gasga, Jose
AU - Montejano-Carrizales, J. Martin
AU - Jose-Yacaman, Miguel
N1 - Funding Information:
This research is supported by Welch Foundation Grant number F-1615. JLB thanks the University of Texas at Austin College of Engineering and Mr. Robert L. Mitchell for support through the Thrust 2000 Robert L. and Jane G. Mitchell Endowed Graduate Fellowship in Engineering. This material is based upon work supported under a National Science Foundation Graduate Research Fellowship (to JLB). JLE acknowledges support received from CONACYT-México. We thank JEOL USA for facilitating SEM analysis with the JSM 7401F, and undergraduate researcher Luis Salazar for helping with the nanocrystal synthesis.
PY - 2005/12/15
Y1 - 2005/12/15
N2 - We report star polyhedral gold nanocrystals synthesized by colloidal reduction with ascorbic acid in water at ambient conditions. We identify two distinct classes of star nanocrystals: multiple-twinned crystals with fivefold symmetry, and monocrystals. These respective classes correspond to icosahedra and cuboctahedra, two Archimedian solids, with preferential growth of their {1 1 1} surfaces. Due to this preferential growth, the {1 1 1} faces of the original Archimedean solids grow to become tetrahedral pyramids, the base of each pyramid being the original polyhedral face. By assuming a star morphology, gold nanocrystals increase their proportion of exposed {1 1 1} surfaces, which possess the lowest surface energy among low-index crystallographic planes for FCC crystals. Thus, we propose that the driving force for star nanocrystal formation could be the reduction in surface energy that the crystals experience. Interestingly, icosahedrally derived star nanocrystals possess a geometric morphology closely resembling the great stellated dodecahedron, a Kepler-Poinsot solid.
AB - We report star polyhedral gold nanocrystals synthesized by colloidal reduction with ascorbic acid in water at ambient conditions. We identify two distinct classes of star nanocrystals: multiple-twinned crystals with fivefold symmetry, and monocrystals. These respective classes correspond to icosahedra and cuboctahedra, two Archimedian solids, with preferential growth of their {1 1 1} surfaces. Due to this preferential growth, the {1 1 1} faces of the original Archimedean solids grow to become tetrahedral pyramids, the base of each pyramid being the original polyhedral face. By assuming a star morphology, gold nanocrystals increase their proportion of exposed {1 1 1} surfaces, which possess the lowest surface energy among low-index crystallographic planes for FCC crystals. Thus, we propose that the driving force for star nanocrystal formation could be the reduction in surface energy that the crystals experience. Interestingly, icosahedrally derived star nanocrystals possess a geometric morphology closely resembling the great stellated dodecahedron, a Kepler-Poinsot solid.
KW - A1. Nanocrystal morphology
KW - A1. Nanostructures
KW - B1. Star nanocrystals
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U2 - 10.1016/j.jcrysgro.2005.09.060
DO - 10.1016/j.jcrysgro.2005.09.060
M3 - Article
AN - SCOPUS:28044433197
SN - 0022-0248
VL - 285
SP - 681
EP - 691
JO - Journal of Crystal Growth
JF - Journal of Crystal Growth
IS - 4
ER -