Ag‐Cu Colloid Synthesis: Bimetallic Nanoparticle Characterisation and Thermal Treatment

Abstract

The Ag-Cu bimetallic colloidal nanoparticles (NPs) were prepared by solvothermal synthesis from metalloorganic precursors in a mixture of organic solvents. The nanoparticles were characterized by dynamic light scattering (DLS) and small angle X-ray scattering (SAXS). The properties of metallic core and organic shell of the nanoparticles were studied by direct inlet probe mass spectrometry (DIP/MS), Knudsen effusion mass spectrometry (KEMS), double-pulse laser-induced breakdown spectroscopy (DPLIBS), and differential scanning calorimetry (DSC). The transmission electron microscopy (TEM) and scanning electron microscopy (SEM) were used for particle characterization before and after thermal analysis. The experiment yielded results that were for AgCu nanoparticles for the first time. The detected liquidus temperature has been compared with the prediction obtained from calculation of the phase diagram of Ag-Cu nanoalloy. The experimental results show that of near-eutectic composition AgCu nanoparticles possess the fcc crystal lattice. Surprisingly, spinodal decomposition was not observed inside the AgCu nanoparticles at temperatures up to 230°C. The depression of the eutectic AgCu melting point was calculated but not observed. The eutectic AgCu microparticles are formed before melting.

Thermal Stability of Oleate‐Stabilized Gd2O2S Nanoplates in Inert and Oxidizing Atmospheres

“…The main ion at m/z 30 characteristic of oleylamine is absent of the mass spectrum, which indicates that there is no significant amount of oleylamine vs . oleates on the surface of the nanoparticles …”

Annealing-induced highly-conductive and stable Cu–organic composite nanoparticles with hierarchical structures

“…Three types of methods to solve this problem have been proposed. The first one is adding alloying elements, such as Ag [8,9] and Ni [10], to enhance its corrosion resistance. For macro-scale materials, alloying is a simple and standard technique; however, for nanosized materials, to control and retain the precise stoichiometry remains a challenge [11].…”

Quantum-Mechanical Assessment of the Energetics of Silver Decahedron Nanoparticles

“…The energies of studied decahedral nanoclusters and nanoparticles were calculated in two different ways which are both connected with quantum-mechanical Density Functional Theory (DFT) [20,21] calculations. The first method is a phenomenological thermodynamic modeling based on the CALPHAD method when the energy of nanoclusters and nanoparticles is approximated by a sum of relevant energy contributions corresponding (i) to a defect-free bulk material and (ii) surface energies and stresses (related to surfaces of a bulk, not nanoparticles) [22][23][24][25][26]. It is customary now that some or all energy contributions used in CALPHAD approach are computed using quantum-mechanical methods.…”

“…The phenomenological thermodynamic approach based on the CALPHAD method is very often used for calculations of the total energy of particles as well as for the prediction of phase diagrams [22][23][24][25][26]43]. The computations use an approximation when bulk variables are applied in the case of nanoparticles but not all properties of the (nano-)particles are included (for example, a structural disorder is sometimes omitted).…”