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Title: Exotic shapes of gold nanoparticles synthesized using plasma in aqueous solution

Journal Article · · Journal of Vacuum Science and Technology. A, International Journal Devoted to Vacuum, Surfaces, and Films
DOI:https://doi.org/10.1116/1.2919139· OSTI ID:21192389
; ;  [1]
  1. Department of Materials, Physics and Energy Engineering, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa, Nagoya 464-8603 (Japan)

Gold nanoparticles with exotic shapes, such as triangle, pentagon, and hexagon, have been synthesized by glow discharge in aqueous solutions. A pulsed power supply was used to generate discharges in the aqueous solutions. Pulse width and frequency were 2 {mu}s and 15 kHz, respectively. Discharges were generated at applied voltages of 1600 and 3200 V. The shapes of the gold nanoparticles and electron diffraction patterns were observed by transmission electron microscopy. The nanoparticles obtained were about 20 nm in diameter. In particular, at the higher voltage of 3200 V, nanoparticles with anisotropic shapes were synthesized. In the initial stages of synthesis, diameter decreased with discharge time as the nanoparticles redissolved in the solution. After discharge for 25 min, nanoparticles with anisotropic shapes appeared. This discharge led to the generation of H{sub 2}O{sub 2} and a decrease in pH as a result of the consumption of OH radicals during the generation of H{sub 2}O{sub 2} and electron donation of H radicals to the solution. After the pH stopped decreasing, H radicals mainly reacted as a reducing agent. The decrease in pH allowed redissolution of the gold nanoparticles. The gold dust particles that were not completely dissolved acted as new seeds for nucleation. Thus, the two reaction steps, nucleation and nuclear growth, occur during the formation of gold nanoparticles with exotic shapes.

OSTI ID:
21192389
Journal Information:
Journal of Vacuum Science and Technology. A, International Journal Devoted to Vacuum, Surfaces, and Films, Vol. 26, Issue 4; Conference: 54. international AVS symposium, Seattle, WA (United States), 14-19 Oct 2007; Other Information: DOI: 10.1116/1.2919139; (c) 2008 American Vacuum Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 1553-1813
Country of Publication:
United States
Language:
English