Themed collection Recent advances in the chemical physics of nanoalloys

Nanoalloys present a rich variety of structures and properties, which depend on both size and composition, and make them suitable for applications in catalysis, plasmonics, magnetic data storage, and biomedicine.

Chemical order effects and intrinsic magnetic properties of well-defined bimetallic L1₀ CoPt-type, B2 FeRh-type and core/shell CoAu-type nanoalloys.

There is a growing interest in the use of nanosystems in biomedical applications. In this perspective, we survey current applications and advances in magnetic nanoparticles used in biomedical applications, so as to understand the material properties that can pave the way for the use of nanoalloys.

Nanoalloys and nanocomposites are widely studied classes of nanomaterials within the context of biological systems. This article presents an overview of methods currently used for nanoalloy and nanocomposite synthesis and characterization, focusing on Au-Ag and FexOy@Au structures as primary components in detection platforms for plasmonic and magnetically enabled plasmonic bio-sensing.

Theoretical models and experimental results for segregation in bimetallic nanoparticles are discussed and compared in this perspective.

Optical absorption spectra of bare (left) and monolayer-protected (right) metal nanoalloys.

Nanoalloys exhibit composition- and size-dependent shapes that are influenced by temperature at equilibrium.

Selective surface-induced destabilization of L1₀ superstructure variants is simulated in FePt nanostructures of diverse dimensionalities.

A melting temperature depression of around 14 °C for Ag–Cu nanoparticles synthesized by a chemical reduction method has been experimentally measured by differential scanning calorimetry (DSC).

XMCD measurements on doped Co clusters in the gas phase reveal their fluctuating spin and orbital magnetic moments.

The dynamics of the electronic density corresponds to a collective charge oscillation, albeit influenced by the inhomogeneity of noble metals.

A non-monotonous variation of the critical temperature as a function of the length of the nanotubes.

A comparison of bimetallic Pt–Ru clusters grown by vapor deposition (VD) and electroless deposition (ED) of Pt on Ru seed clusters.

Melting temperature dependence on the radius of CuPt clusters by CALPHAD and atomistic molecular dynamics simulations. The formation of a supercooled region for 3 nm particle is highlighted by the huge hysteresis during the freezing process.

Nanoalloy energy landscapes explored in continuous and discrete metric spaces simultaneously.

Insights into the mixing of gold and copper atoms at the nanoscale for the controlled synthesis of Au–Cu nanoalloys.

Global optimization of 1 : 1 compositions of (Co–Pd)_N/2 up to N = 150 and all compositions of 34- and 38-atom binary clusters has been performed using a genetic algorithm, coupled with the Gupta empirical potential to model interatomic interactions.

The predicted spinodal decomposition of metastable Ag–Cu nanoparticles was experimentally induced (and detected) by heating on an high temperature X-ray diffractometer (HT XRD).

Core–shell nanoparticle properties strongly dependent on cluster size and composition.

The relative electrical resistivity, Gibbs free energy function and crystallite size of the Ag–28% Cu nanopowders as a function of temperature.

Pt_YCo_1−Y-core@Co-rich-subsurface@Pt-shell structure is identified in several nm large Pt–Co particles using X-ray photoelectron spectroscopy and an optimization method based on density-functional calculations.

The global minimum for a 309-atom icosahedral Au–Cu nanoalloy is identified, with potential application for electrochemical production of CO.

(Au–Ag)_N nanoalloy clusters made up of N = 10–15 atoms increase by an order of magnitude the room temperature photoemission intensity of Er³⁺ in silica, better than monometallic Au_N clusters of the same size.

A first-principles investigation of the effect of the doping of golden cages of 32 atoms is proposed.

Operando PXRD shows slow diffusion kinetics of controllable, reversible segregation in a PdAg nanoalloy that is explained by atomistic modeling.

In situ transformation of local structure and hyperfine interactions are simultaneously followed in real time during temperature annealing of metallic glasses.

The paper presents a first comprehensive experimental investigation of the structural evolution of eutectic Ag–Cu nano-alloys, as confined between inert AlN barriers in a nano-multilayered configuration, upon fast heating.

Ageing of nanoalloys: the nanoparticle passes through a metastable onion-like configuration on its way to its equilibrium core–shell structure.

A new coarse-grained layer model (CGLM) predicts symmetry-breaking transitions in Pt–Ir nanoparticles furnishing a unique nanophase diagram.

AuRu bimetallic catalysts have been prepared by sequential deposition of Au on Ru or vice versa obtaining different nanostructures: when Ru has been deposited on Au, a Au_core–Ru_shell has been observed, whereas the deposition of Au on Ru leads to a bimetallic phase with Ru enrichment on the surface.

Formation of PdZn intermetallic nanoalloys selective for propane dehydrogenation tracked using in situ synchrotron XRD.

Density functional theory based global geometry optimization has been used to demonstrate the crucial influence of the geometry of the catalytic cluster on the energy barriers for the CO oxidation reaction over Pd-based bimetallic nanoalloys.

In situ heating TEM reveals the influence of the nanocrystallinity on the ordering transition of CoPt nanoalloys.

For increasing tin concentrations PtSn nanoparticles of similar size show a monotonically increasing selectivity towards crotylalcohol and a volcano like activity.

Anion photoelectron spectroscopy and DFT calculations study on Au_nRh_m (n = 1–7 and m = 1–2). PES spectra, vertical and adiabatic detachment energies, are compared. The characteristic planarity for gold clusters is preserved for many of the bimetallic clusters.

Size-selected 9 nm Pt_xY nanoparticles have recently shown an outstanding catalytic activity for the oxygen reduction reaction, representing a promising cathode catalyst for proton exchange membrane fuel cells (PEMFCs).

A novel method for modelling of size-dependent phase diagrams combines the CALPHAD method and ab initio calculations of surface stresses.

Adsorption and nucleation of different transition metals on alumina/Ni₃Al(111) have been studied to shed light on the first stages of the synthesis of supported nanoparticles, rationalizing the experimental evidence that Pd seeding is the optimal choice to give rise to highly ordered patterns.

Fe–Au nanoparticles maintain almost a constant magnetic moment of ∼2.8 μ_B, which is 27% enhancement from the bulk value.

We present a detailed study of the catalytic activity of Au/Pd nanoalloys with Au : Pd molar ratio 75 : 25 synthesized using spherical polyelectrolyte brushes (SPB) as carrier system.

Enhanced catalytic activity of the bimetallic Ir–Au/TiO₂ catalyst, prepared by sequential deposition–precipitation with urea, in the total oxidation of propene due to a surface Ir⁰–Au⁰ synergism.

Au–Rh and Au–Pd nanoalloys synthesized by colloidal methods and immobilized on rutile titania nanorods are more stable than their monometallic counterparts for tetralin hydrogenation in the presence of sulfur.

Modular construction of platinum–titanium dioxide clusters, which exhibit multiple Pt cores with a preferred size of 30 ± 6 atoms.

An ab initio theoretical study on icosahedral Fe–Pt clusters – one of the most interesting nanoalloys with high application potential.

Ni–Au synergism on Al₂O₃ and TiO₂ generates increased surface reactive hydrogen with elevated reaction rates in the hydrogenation of nitroarenes.

The crossovers among the most abundant structural motifs (icosahedra, decahedra and truncated octahedra) of Pd–Au nanoalloys are determined theoretically in a size range between 2 and 7 nm and for three compositions equivalent to Pd₃Au, PdAu and PdAu₃.

Simulated 2-dimensional cyclic voltammetry for nanoalloys with a hybrid ensemble scheme in Monte Carlo simulation based on the cluster expansion method.

Structure and thermodynamics of CuNi nanoalloys determined by a new DFT-fitted atomistic potential.

In this work, we report a facile synthesis route, structural characterization, and full atomistic simulations of gold–palladium nanoalloys.

Metastable nanoalloys, metal-oxide nanocrescents and metal@oxide nanoshells are generated by laser ablation in liquid solution (LASiS).

The vibrational density of states (VDOS) of metal nanoparticles can be a fingerprint of their geometrical structure and determine their low-temperature thermal properties.

We show how alloying and excessive de-alloying affect ORR activity and the structural integrity of PEMFC nanocatalysts.

We report on the theoretical discovery of a novel magnetic alkali-like superatom, and discuss its possible spintronics or biomedical applications.