Mechanistic Investigations of the Synthesis of Size-Tunable Ni Nanoparticles by Reduction of Simple NiII Diamide Precursors

5 years ago

Mechanistic Investigations of the Synthesis of Size-Tunable Ni Nanoparticles by Reduction of Simple NiII Diamide Precursors

Pierre Lecante, Nicolas Mézailles, Christian Pradel, Koyel X. Bhattacharyya

Herein, we present a detailed study of the conversion of a nickel(II) diamide precursor to size-tunable, monodisperse nickel nanoparticles (NPs). The thermal decomposition of nickel(II) dioleylamide, synthesized either independently or in situ, resulted in the formation of Ni NPs without the coproduction of water. Mechanistic studies were conducted on the stability and reduction pathway of the NiII precursor, and on the consequent particle formation. Variations in the ratio of trioctylphosine (TOP) to nickel allowed size tunability, which resulted in nanoparticles that ranged in size from 4 to 11 nm in diameter. The DFT calculations support a mechanistic pathway that involves nickel reduction by imine formation. This water-free method was extended to the synthesis of water-sensitive M0 NPs (M=Fe, Co). Precursor analysis: A nickel(II) diamide precursor was used to form size-tunable, monodisperse nickel nanoparticles (NPs, 4–11 nm; see figure) without the coproduction of water. Mechanistic studies elucidated the reduction pathway for the precursor and particle formation. The polymeric state of the precursor was reproducibly found to affect the size and shape of the resulting particles. The method was extended to the synthesis of water-sensitive M0 NPs (M=Fe, Co).

Publisher URL: http://onlinelibrary.wiley.com/resolve/doi

DOI: 10.1002/chem.201701258