Growth of highly crystalline nickel particles by diffusional capture of atoms

Abstract

We report a new approach to achieve growth of highly crystalline nickel nanoparticles over an extended range of sizes (up to 100 nm in diameter) and time scales (up to several hours) by diffusional transport of constituent atoms. The experimental procedure presented offers control of the morphology of the resulting particles and yields base metal nanocrystals suitable for epitaxial deposition of noble metal shells and the preparation of materials with improved catalytic properties. The reported precipitation system also provides a good model for testing a diffusion-driven growth mechanism developed specifically for the reduction process described.

Phase transitions in systems with aggregation and shattering

“…2. To establish this assertion analytically we first notice that c 1 (τ ) given by (10) reaches minimum when τ = 2, from which the minimal possible value is…”

“…To understand this surprising behavior we notice that the monomer density given by (10) is physically applicable as long as c 1 ≥ 0. For sufficiently large shattering rates the monomer density is always positive, while for smaller rates c 1 (τ ) first vanishes at a certain τ max (λ).…”

Synthesis of dispersed metal particles for applications in photovoltaics, catalysis, and electronics

“…The spatial transport of solute/suspension matter is typically diffusional [24,64]. The constituent units from which particles are formed, frequently called monomers or singlets, in nanosize synthesis are solute species: atoms, ions, molecules.…”

“…8) advances faster than the smaller-s side. Thus, the peak generally broadens during growth [24,65].…”

“…Experimental data and their model analysis for such nickel particle growth in a range of sizes from 30 to 100 nm were reported [22,24] under conditions that allow a direct verification of the diffusional transport as the process controlling the growth. Data were obtained for several times of particle growth, and used in a model of diffusional transport of the monomers (nickel ions).…”