Silver nanostructures from Ag(CN) sub(2) super(-) reduction by citrate ions in the presence of dodecyl sulfate and Cu super(2+) ions. Synthesis and characterization

• Published in: Journal of nanoparticle research : an interdisciplinary forum for nanoscale science and technology Vol. 16; no. 2; pp. 1 - 14
• Main Authors: Lopez-Miranda, A, Viramontes-Gamboa, G, Lopez-Valdivieso, A
• Format: Journal Article
• Language: English
• Published: 01.02.2014
• Subjects: Nanoparticles; Nanostructure; Nanowires; Rate constants; Silver; Sulfates; Synthesis; Texture
• ISSN: 1388-0764; 1572-896X
• DOI: 10.1007/s11051-014-2244-2

The synthesis of silver nanoparticles has been investigated using Ag(CN) sub(2) super(-) species as precursor, citrate ions as reducing agent, and dodecyl sulfate ions as stabilizer, at pH 11 and 97 degree C, in a batch stirred glass reactor. The role of Cu super(2+) ions in the synthesis was also studied. Bird-of-paradise flower-type nanostructures composed of AgCN nanowires having inside Ag and AgCN nanoparticles were produced in the absence of Cu super(2+) ions. The nanostructures slowly grew and transformed to AgCN nanowires with embedded Ag and AgCN nanoparticles, having a mean size of 9.7 plus or minus 3.6 nm. The presence of Cu super(2+) ions in the synthesis significantly enhanced the production of the nanostructures. Nanowires having a thickness of 63 plus or minus 33 nm and length of up to 20 mu m were produced. Cu super(2+) ions also simultaneously lead to the synthesis of ordinary free Ag nanoparticles with a bimodal size distribution (mean sizes of 9.9 plus or minus 3.9 and 65.5 plus or minus 27 nm) and a low experimental formation kinetic rate constant of 1.22 10 super(-4) s super(-1). Feasible mechanisms are presented for the origin of the AgCN nanowires, Ag and AgCN nanoparticles inside the nanowires, and for the free Ag nanoparticles. UV/Vis spectrometry was used to measure the surface plasmon resonance of the nanoparticles and the synthesis kinetic rate constant of the free Ag nanoparticles. ATR-FTIR spectroscopy, EDS-SEM, EDS-TEM, and HRTEM were used to characterize the size, crystal structure, texture, and chemical composition of the synthesis products.