Gold Nanowire Networks: Synthesis, Characterization, and Catalytic Activity

• Type: Article in International Scientific Journal
• Date: 2011

Authors

Mariana Chirea (Author) FCUP; Andreia Freitas (Author) Other; Bogdan S Vasile (Author) Other; Cristina Ghitulica (Author) Other; Carlos M Pereira (Author) FCUP; Fernando Silva (Author) FCUP

Journal

Title: Langmuir

Vol. 27 No. 8

Pages: 3906-3913

ISSN: 0743-7463

Publisher: American Chemical Society

Indexing

ISI Web of Knowledge - 119 Citations

Scopus - 131 Citations

Scientific classification

FOS: Engineering and technology > Materials engineering

Other information

Authenticus ID: P-002-SFS

DOI: 10.1021/la104092b

Abstract (EN): Gold nanowire networks (AuNWNs) with average widths of 17.74 nm (AuNWN1) or 23.54 nm (AuNWN2) were synthesized by direct reduction of HAuCl4 with sodium borohydride powder in deep eutectic solvents, such as ethaline or reline, at 40 degrees C. Their width and length were dependent on the type of solvent and the NaBH4/HAuCl4 molar ratio (32 in ethaline and 5.2 in reline). High resolution transmission electron microscopy (HR-TEM) analysis of the gold nanowire networks showed clear lattice fringes of polycrystalline nanopowder of d = 2.36, 2.04, 1.44, and 1.23 angstrom corresponding to the (111), (200), (220), or (311) crystallographic planes of face centered cubic gold. The purified AuNWNs were used as catalysts for the chemical reduction of p-nitroaniline to diaminophenylene with sodium borohydride in aqueous solution. The reaction was monitored in real time by UV-vis spectroscopy. The results show that the reduction process is six times faster in the presence of gold nanowire networks stabilized by urea from the reline (AuNWN2) than in the presence of gold nanowire networks stabilized by ethylene glycol from ethaline (AuNWN1). This is due to a higher number of corners and edges on the gold nanowires synthesized in reline than on those synthesized in ethaline as proven by X-ray diffraction (XRD) patterns recorded for both types of gold nanowire networks. Nevertheless, both types of nanomaterials determined short times of reaction and high conversion of p-nitroaniline to diaminophenylene. These gold nanomaterials represent a new addition to a new generation of catalysts: gold based catalysts.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 8