Light-Induced Selective Deposition of Metals on Gold-Tipped CdSe-Seeded CdS Nanorods

Abstract

We introduce a facile approach for the selective deposition of metals on Au-tipped CdSe-seeded CdS nanorods that exploits the transfer of electrons from CdS to the Au tips upon UV excitation. This light-induced deposition method was used for the deposition of Pd under mild conditions, which produced a Pd/Au alloyed tip while preserving the rest of the semiconductor nanoarchitecture. The highly site-selective deposition method was extended to the deposition of Fe, yielding monodispersed, structurally complex Au core/Fe(x)O(y) hollow shell-tipped semiconductor nanorods. These structurally well-defined rods were found to exhibit magnetic functionality. The synthetic strategies described in this work expand on the range of metals that can be deposited on heterostructured semiconductor nanorods, opening up new avenues for the hierarchical buildup of structural complexity and therefore multifunctionality in nanoparticles.

Recent Developments in the Synthesis of Metal-Tipped Semiconductor Nanorods

“…In order to circumvent this problem, Li et. al., 59 reported a deposition approach where existing metal tips in a metal-semiconductor nanostructure are used as heterogeneous nucleation sites for the subsequent deposition of a different metal under conditions of UV photo-irradiation Fig. 14 illustrates the resulting structures when Pd precursors are exposed to Au-tipped CdSe seeded CdS nanorods under UV excitation.…”

Highly selective growth of TiO2 nanoparticles on one tip of CdS nanowires

“…Two main routes have typically been used for growth of such heterostructures, with the semiconductor nanowires serving as a template for the metal/semiconductor growth. The first route employs light-induced growth of the metal/semiconductor onto semiconductor nanowires [39][40][41][42][43][44]. The metal/semiconductor deposition is promoted and controlled by UV light irradiation under anaerobic conditions, which is assigned to electrochemical Ostwald ripening of the metal onto the location next to the metal/semiconductor seed through localizing electrons in metal/semiconductor -semiconductor heterostructures.…”

“…It is noted that selective growth of TiO 2 cannot occur in the CdS nanostructures with nonpolar growth direction e.g. [36][37][38][39][40][41][42][43][44][45] and . As is well known, for the polar wurtzite CdS nanowires, nonpolar facets have much lower growth rates that the basal, polar facets, and therefore the nanocrystals can be preferentially grown along unique [0001].…”

Synthesis of CdS Nanocrystals with Different Shapes via a Colloidal Method

“…A variety of methods have been devised to prepare 1D CdS NCs, such as template method, hot-injection route, polymer controlled growth, and liquid-phase colloidal syntheses. [13][14][15][16][17][18][19][20][21] Among these methods, the hot-injection approach has been proved to be an effective way for the synthesis of high-quality 1D nanostructures. 13,15,19 However, few investigations were focused on the synthesis of highly uniform, different rod-shaped CdS NCs via a hot-injection colloidal method.…”