Ternary hybrid nanostructures of Au–CdS–ZnO grown via a solution–liquid–solid route using Au–ZnO catalysts

Abstract

Multi-component nanostructures of Au-CdS-ZnO with a novel morphology were synthesized by a non-conventional strategy where seeded growth is combined with solution-liquid-solid (SLS) growth. Each of these synthetic routes is used for growing a different domain of the final heterostructure, where ZnO rods are grown first on Au nanoparticles via heterogeneous nucleation while CdS is later grown between these two domains via SLS, using the Au tip of the preformed Au-ZnO as a catalyst. The in situ alloying of the Au tip with Cd enabled the metal tip to function as an SLS catalyst at a relatively mild reaction temperature which is lower than the melting point of pure Au.

Solution–Liquid–Solid Growth of One-Dimensional Metal-Oxide Nanostructures Assisted by Catalyst Design

“…metals. 21,31,40 The formation pathways of each metal (In, Sn)-gold alloy were specifically designed because of the difference in the redox potential between the metal ions. Tin(II) acetate (Sn(ac) 2 ) has a higher tendency to undergo reduction than indium(III) acetylacetonate (In(acac) 3 ); for example, Sn 2+ has a reduction potential of E°= −0.14 V, 41,42 while for In 3+ , it is E°= −0.34 V. 42,43 Therefore, the synthetic path (Scheme 1) was chosen with this difference in mind: the Au-Sn alloy is formed via a "hot-injection" synthesis, while the Au-In alloy is prepared using a "heat-up" approach.…”

“…shell, heterodimer), as reported by the groups of Schaack, Mirkin, and others. 11,27−30 As a wet-chemistry colloidal synthesis, the SLS offers (i) a controllable 1D diameter; 13 (ii) use of surfactants that facilitate dispersibility in a liquid phase and allows chemical functionalization; 13 (iii) relatively easy integration of distinct materials into a hybrid nanostructure; 9,31,32 and (iv) a scalable reaction path at relatively mild conditions (<400 °C, under ambient pressure). 19 Thus far, semiconductors of groups III− V, II−VI, and IV were successfully synthesized using this methodfor example, binary M-pnictides (P, As) 24 and Mchalcogenides (S, Se, Te).…”

Selective Growth of Metal Sulfide, Metal, and Metal-Alloy on 2D CdS Nanoplates

“…In some cases, synergy between the two domains allows enhancement of the original properties and even leads to novel properties that did not exist in the separate domains (Cozzoli et al, 2006;Urban et al, 2007;Shaviv and Banin, 2010). The constantly increasing knowledge in colloidal NP synthesis (e.g., formation mechanisms, size and distribution, dimensionality and shape control, composition of constituents, surface composition-ligand type, coverage, and functionality) (Carbone and Cozzoli, 2010) provides a solid ground for the design of HNSs with domains consisting of a wide range of materials such as metals (Naskar et al, 2017), metal alloys (Habas et al, 2008), metal chalcogenides (Banin et al, 2014;Flomin et al, 2017), metal oxides (Chang et al, 2017), carbon based materials (Zhi et al, 2008), and polymers (Liu et al, 2010). HNSs have been shown useful for a variety of applications such as medicinal uses (Zhang et al, 2018), photocatalysis (Tongying et al, 2012;Waiskopf et al, 2018), and other energy-related applications (Cho et al, 2019).…”

Photocatalysis with Pt–Au–ZnO and Au–ZnO Hybrids: Effect of Charge Accumulation and Discharge Properties of Metal Nanoparticles

“…However, the metal–semiconductor interface is typically nonepitaxial . A combination of the above methods might give the possibility to prepare three-component hybrid structures with multiple functionalities (optical, optoelectronic, and/or magnetic), , while still retaining the epitaxial interface between the metallic and semiconductor components.…”