Controlled overgrowth of Pd on Au nanorods

Abstract

In this paper, we present a detailed, systematic study of the controlled overgrowth of Pd on Au nanorods.Pd nanoshells with fine-controlled dimensions and architectures were overgrown on single-crystalline Au nanorods through seed-mediated growth using H 2 PdCl 4 as the Pd precursor and ascorbic acid as the reducing agent in the presence of cetyltrimethylammonium chloride (CTAC) or cetyltrimethylammonium bromide (CTAB) as the surface capping agent. The effects of surface capping agent, ascorbic acid to H 2 PdCl 4 ratio, reaction temperature, and structure-directing foreign ions, such as Ag + , on the dimensions and architectures of the resulting Au@Pd core-shell heteronanostructures were systematically studied.At 30 °C, Au nanorods coated with polycrystalline Pd shells were obtained using CTAC as the surface capping agent, while single-crystalline Au@Pd core-shell nanocuboids formed in the presence of CTAB.The thicknesses of the polycrystalline and single-crystalline Pd shells were fine-controlled by adjusting the molar ratio of ascorbic acid to H 2 PdCl 4 . At an elevated reaction temperature of 60 °C, irregularly shaped and cylindrical co-axial core-shell nanorods were obtained in CTAC and CTAB, respectively. By introducing Ag + ions into the Pd growth solution, Au nanorods coated with segregated Pd nanoislands and dumbbell-like core-shell heteronanostructures were obtained as a consequence of the underpotential deposition of Ag and sustainable galvanic replacements that concurred during the Pd overgrowth processes.The effects of the Pd shell dimensions and morphologies on the plasmonic properties of the Au@Pd core-shell nanostructures were also investigated.

Facile synthesis of Au/Pd nano-dogbones and their plasmon-enhanced visible-to-NIR light photocatalytic performance

“…Au NRs were prepared by a modied seed-mediated growth method. 29,30 Generally, the seed solution was obtained by reduction of HAuCl 4 $3H 2 O (0.5 mM, 5 mL) in CTAB (0.2 M, 5 mL) solution with ice-cold NaBH 4 (6 mM, 1 mL). The seed solution was aged at room temperature for 30 min before use.…”

Suzuki‐Miyaura Cross‐Coupling Using Plasmonic Pd‐Decorated Au Nanorods as Catalyst: A Study on the Contribution of Laser Illumination

“…[15,19] This higher Pd nanoparticle concentration at the tips is desirable, since the longitudinal LSPR has a much larger absorption cross-section than its transversal counterpart, giving stronger local fields at the tips of the particle than on the sides. The particles applied in our study are rod shaped with average dimensions of 107 � 8 nm and an average width of 49 � 5 nm (n = 42), having an aspect ratio of 2.2.…”

“…The tips of the rods show a higher concentration of Pd particles than the sides, which is in agreement with earlier publications. [15,19] This higher Pd nanoparticle concentration at the tips is desirable, since the longitudinal LSPR has a much larger absorption cross-section than its transversal counterpart, giving stronger local fields at the tips of the particle than on the sides. The plasmonic characteristics of the particles were measured with UV-VIS in diluted aqueous dispersion, as received.…”

Fabrication of label-free electrochemical food biosensor for the sensitive detection of ovalbumin on nanocomposite-modified graphene electrode

“…Nanomaterials were prepared according to literature with modifications [30]. In brief, 200 mg Fe 3 O 4 was mixed in 25 mL distilled water.…”

“…Therefore, 45 min was chosen a standard blocking time by BSA for the fabrication of the food biosensor. Finally, the four different reaction time (15,30,45 and 60) between Ova-Ab and Ova to form an immunocomplex was also examined. Among the four different tested time, biosensor demonstrated that immunocomplex formation reached to saturation point at 30 min and get stabilized ( Figure 2D).…”