Boron doped graphene wrapped silver nanowires as an efficient electrocatalyst for molecular oxygen reduction

Abstract

Metal nanowires exhibit unusually high catalytic activity towards oxygen reduction reaction (ORR) due to their inherent electronic structures. However, controllable synthesis of stable nanowires still remains as a daunting challenge. Herein, we report the in situ synthesis of silver nanowires (AgNWs) over boron doped graphene sheets (BG) and demonstrated its efficient electrocatalytic activity towards ORR for the first time. The electrocatalytic ORR efficacy of BG-AgNW is studied using various voltammetric techniques. The BG wrapped AgNWs shows excellent ORR activity, with very high onset potential and current density and it followed four electron transfer mechanism with high methanol tolerance and stability towards ORR. The results are comparable to the commercially available 20% Pt/C in terms of performance.

Facile preparation of flexible and highly stable graphene oxide-silver nanowire hybrid transparent conductive electrode

“…The Ag 3d spectrum (figure 7(e)) of AgNWs film exhibits two strong peaks, 3d 3/2 and 3d 5/2 , located at respectively 373.81 and 367.81 eV, corresponding well to Ag(I) [46], which is attributed to Ag 2 O. After exposing at 80°C and 75% RH in the air for 16 days, however, the Ag 3d spectrum of GO/AgNWs film (figure 7(f)) shows the two peaks in 374.24 eV (Ag 3d 3/2 ) and 368.24 eV (Ag 3d 5/2 ) corresponding well to Ag [47], which provides direct evidence that silver nanowires have not been oxidized under the protection of GO layer. Figure 8 shows the mechanical stability of AgNWs and GO/AgNWs (C Go =0.5 mg·ml −1 ) films.…”

Silver Nanowire‐Based Catalysts for Oxygen Reduction Reaction in Alkaline Solution

“…[7] The crystal structure of AgNWs has been studied in the literature. [29,30,45] According to measurements conducted by Alia et al it was observed that the AgNWs are round and do not have one certain facet, rather a mixture of them. [29] The RDE polarization data was used for Tafel analysis (Figure 2h).…”

“…On the one hand, the value of the current density in the diffusion-limited region of the polarization curve obtained after the test is slightly higher than that obtained at the initial polarization curve. This can be explained by the fact that a small amount of hydrogen peroxide formed during the repetitive potential cycling breaks down the organic impurities, i. e. PVP that was used to synthesize and store the AgNWs, [30,34,51] and cleans the electrode surface and increases the electrocatalytic activity of the electrode. On the other hand, the halfwave potentials decreased by 16 mV for 120 nm and 12 mV for 35 nm AgNWs, with a slight increase of 4 mV for 90 nm AgNW catalyst.…”

“…[29] Nair et al synthesized a highly efficient ORR catalyst, which consisted of boron-doped graphene slabs packed with Ag nanowires (BG-AgNW). [30] The ORR catalyzed by this hybrid material proceeded by a full 4-electron pathway. The BG-AgNW catalyst showed high stability and less than 2 % peroxide yield at À 0.8 V. In recent works where AgNWs were integrated into graphene aerogel the ORR also proceeded through the direct 4-electron pathway.…”

Ruthenium oxide modified hierarchically porous boron-doped graphene aerogels as oxygen electrodes for lithium–oxygen batteries

“…Moreover, graphene can be easily modied to enhance its properties or to endow it with new properties on demand. For instance, the chemical doping of graphene with various heteroatoms (N, B, S, and P) [12][13][14][15] or the construction of a 3D porous structure aerogel 16,17 both can provide enhanced performance. Recently, combining the advantage of boron-doping with a graphene aerogel structure, a simple one-pot hydrothermal method is adopted to prepare a 3D boron-doped graphene aerogel framework (B-HRG).…”