l-Arginine-assisted electrochemical fabrication of hierarchical gold dendrites with improved electrocatalytic activity

Abstract

Shape and size c ontrol of gold (Au) nanocrystals plays important roles in their catalytic and optical properties. Hierarchical Au nanodendrites were directly electrodeposited on a glassy carbon electrode (GCE) using L-arginine as a growth-directing agent, while there is no seed, template, or surfactant involved. It was found that the experimental conditions such as the applied potentials, concentrations of HAuCl 4 and L-arginine, and deposition time were essential to the final morphology of the Au deposits. The as-synthesized Au nanocrystals displayed enhanced electrocatalytic activity and improved stability for ethylene glycol (EG) oxidation in acidic media as compared to Au nanoparticles.

Shape-controlled electrochemical synthesis of Au nanocrystals in reline: control conditions and electrocatalytic oxidation of ethylene glycol

“…7a). Moreover, this value is much higher than the irregular Au NCs (2.33), commercial Au electrode (2.16) and previously reported catalysts (Table 1), 7,[51][52][53][54][55][56] showing that the Au NSs have better poisoning-resistant ability and steady-state behaviour for EG oxidation. Fig.…”

“…51 The electrocatalytic activities of the Au NSs (with sharply pointed structures at the applied potential of À0.60 V, vs. Pt), the irregular Au NCs (with rod-like structures at the applied potential of À0.70 V, vs. Pt) and commercial Au electrode towards EG oxidation were evaluated by CV in 0.5 M NaOH solution containing 0.10 M EG (Fig. 7a).…”

“…48,51 Larger ratio of the peak currents in the forward potential scan (i f ) to the reverse scan (i r ) would bring better poisoning-resistant ability of the electrodes for EG oxidation. The oxidation peak in the backward scan corresponds to the electrochemical oxidation of CO and other adsorbed species.…”

Bioinspired One-Step Synthesis of Pomegranate-like Silica@Gold Nanoparticles with Surface-Enhanced Raman Scattering Activity

“…Though the SNPs can possibly form at arginine concentration as low as 0.2 mM, 41 the pomegranate-like structures require at least 8 mM of arginine, indicating that a major portion of arginine contributes to affect Au. Arginine interacts with HAuCl4 through forming arginine-AuCl4 complex 48 and reduces it to Au. UV-Vis spectra shows that the peak of AuCl4at 305 nm disappears after dissolving arginine ( Figure S4), suggesting the formation of arginine-AuCl4 complex.…”

One Dimensional AuAg Nanostructures as Anodic Catalysts in the Ethylene Glycol Oxidation

“…Researchers have focused on alloying as an amenable solution to producing more sophisticated catalysts that are not only cheaper, but also offer improved atom utilisation and catalytic properties [13][14][15][16]. In particular, Au-and/or Ag-containing alloys have emerged as effective anodic catalysts for fuel cell applications, most notably for the EG oxidation reaction (EGOR) [11,[17][18][19]. Due to advances in synthetic methods, these noble metal nanomaterials can be produced in a broad range of shapes and sizes, making it possible to manipulate catalyst design [20][21][22][23][24].…”