A Facile Room-Temperature Synthesis of Gold Nanowires by Oxalate Reduction Method

Abstract

Polycrystalline gold nanowires were synthesized by a simple chemical reduction method using potassium oxalate as the reducing and capping agent along with polyvinylpyrrolidone (PVP) as the co-capping agent at room temperature. Different molar concentration ratios of HAuCl 4 and potassium oxalate were studied for the synthesis of Au nanowires. Kinetics studies for Au colloid formation were carried out using UV-vis spectroscopic technique for the various concentration ratios of the reactants. As the concentration of oxalate was increased, the rate of reduction as well as particle growth was found to increase. XRD and TEM analyses revealed the formation of polycrystalline Au nanowires with a preferential growth of the {111} facet. In the absence of PVP, no Au colloid was formed. Studies revealed that the formation of the Au nanowire was due to the bridging nature of the oxalate dianion. The formation of Pt nanowires further supported the role of oxalate when the same method was adopted for the synthesis of Pt nanowires without using PVP. A plausible mechanism was proposed for the formation of Au nanowires explaining the role of oxalate.

A Rapid Synthesis of Oriented Palladium Nanoparticles by UV Irradiation

“…As per the literature, this complex can be synthesized by the reaction of Pd(OH) 2 and oxalic acid [ 19 ]. In the case of Pt also, a similar kind of oxalate complex with the wire morphology has been observed [ 20 ]. In the absence of oxalate, irradiation of PdCl 2 solution has not yielded any Pd nanoparticles even after 30 min of UV irradiation.…”

“…High reducing ability and photosensitivity of oxalate di anions are responsible for the rapid decomposition [ 22 ]. Since the standard reduction potentials of Pd ( E 0 (Pd 2+ /Pd) = 0.951 V) [ 23 ] and oxalate di anion ( E 0 (2CO 2 /C 2 O 4 2− ) = −0.49 V) [ 20 ] are favourable, decomposition occurs rapidly under UV irradiation to yield metallic Pd as shown in Eq. 2.…”

Recent Advances in the Liquid‐Phase Synthesis of Metal Nanostructures with Controlled Shape and Size for Catalysis

“…Polycrystalline Au nanowires were formed with a preferential growth of the (111) facet (94). Growth of colloidal gold nanowires (along with nanostars) was shown to be induced by Pd doping (95).…”

Comparative Study of Synergistic Effects of Antibiotics with Triangular Shaped Silver Nanoparticles, Synthesized Using UV-Light Irradiation, on <i>Staphylococcus aureus</i> and <i>Pseudomonas aeruginosa</i>

“…This is due to the high photosensitivity of Ag 2 C 2 O 4 [19]. The decomposition of oxalate occurs rapidly under UV radiation to yield metallic Ag as shown in Equation (1) because this decomposition of Ag 2 C 2 O 4 is thermodynamically favourable due to the suitable reduction potentials of oxalate [20].…”