Selective control of fcc and hcp crystal structures in Au–Ru solid-solution alloy nanoparticles

Abstract

Binary solid-solution alloys generally adopt one of three principal crystal lattices—body-centred cubic (bcc), hexagonal close-packed (hcp) or face-centred cubic (fcc) structures—in which the structure is dominated by constituent elements and compositions. Therefore, it is a significant challenge to selectively control the crystal structure in alloys with a certain composition. Here, we propose an approach for the selective control of the crystal structure in solid-solution alloys by using a chemical reduction method. By precisely tuning the reduction speed of the metal precursors, we selectively control the crystal structure of alloy nanoparticles, and are able to selectively synthesize fcc and hcp AuRu3 alloy nanoparticles at ambient conditions. This approach enables us to design alloy nanomaterials with the desired crystal structures to create innovative chemical and physical properties.

Synthesis of Colloidal Metal Nanocrystals: A Comprehensive Review on the Reductants

“…Organic compounds such as alcohols, polyalcohols (polyols), and phenols are attractive for the synthesis of colloidal metal nanocrystals as they can play multiple roles in a reaction, acting as a solvent, and/or stabilizer, in addition to a reductant . Among various alcohols, methanol and ethanol are the most commonly used because of their abundance and relatively lower prices than other alcohols such as n‐propanol, n‐butanol, and 1‐hexanol . In general, primary alcohols always work as reductants due to their superior reactivity relative to secondary and tertiary alcohols.…”

New Aspects of Platinum Group Metal‐Based Solid‐Solution Alloy Nanoparticles: Binary to High‐Entropy Alloys

“…The first example of crystal structure control in a binary alloy by using a chemical reduction method was reported in 2018 in the Au‐Ru system . The proposed strategy was as follows: the crystal structure of binary alloy NPs is dominated by the nuclei structure.…”

“…When monitored by UV/Vis, we found that RuCl 3 is reduced earlier than HAuBr 4 for the synthesis of hcp‐AuRu 3 NPs (Figure d, e). By using the CV method, we further found that the reduction potential of [AuBr 4 ] − with CTAB was lower than that without CTAB (0.768 vs. 0.856 V), which can be explained by the formation of a complex between [AuBr 4 ] − and CTAB …”

A CTAB-mediated antisolvent vapor route to shale-like Cs4PbBr6 microplates showing an eminent photoluminescence

“…As one of the most common shape-directing agents, the cationic surfactant CTAB has always been a widely utilized in the synthesis of functional materials. 40,41 Fig. S5a and S5b † show the results of the same amount of CTAB were respectively added in DMF and toluene.…”

“…Cs + , Pb 2+ , Br À ) and CTAB will be recrystallized together due to the increase of toluene content in the reaction solution. Furthermore, it is well known that (i) CTAB can be facilely self- assembled to form layered micelles when its concentration in a solution is higher than the critical concentration 40,41 and (ii) the Gibbs free energy of heterogeneous nucleation is generally lower than that of homogeneous nucleation. 42,43 On the basis of the above information and our experimental results, we infer that, under a slow crystallization process like our case, the layered structure CTAB micelles may act as the so templates and in turn direct the growth process of cesium lead bromide compound, thus leading to the formation of shale-like Cs 4 PbBr 6 microplates.…”