Facile synthesis of Cu/Ni alloy nanospheres with tunable size and elemental ratio

Abstract

We report a facile synthesis of copper/nickel (Cu/Ni) alloy nanospheres in high purity and with tunable, well-controlled sizes and elemental ratios. The success of this synthesis relies on the use of one-pot, direct thermal reduction of a Cu and Ni precursor mixture in the presence of trioctylphosphine (TOP) and oleylamine (OAm) at an elevated temperature to form Cu/Ni alloy nanoparticles with a spherical shape and uniform size. Their sizes could be readily tuned in the range of 6.9-27.3 nm by simply varying the volume of TOP added to the reaction solution. The elemental ratio of Cu to Ni in resultant products was found to remain the same as that in the precursor, which offers a simple way to manipulate the composition of Cu/Ni alloy nanospheres. We also tested the catalytic performance of as-prepared Cu/Ni alloy nanospheres and evaluate the effect of size and elemental ratio using the reduction of 4-nitrophenol as the model reaction. The current strategy enables the size and composition controlled synthesis of Cu/Ni alloy nanomaterials and could find important use in the fabrication of other types of bimetallic alloy nanomaterials with desired sizes and compositions for catalytic purposes.