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Research & Reviews: Journal of Material Sciences | ISSN: 2321-6212 | Volulme 6
November 07-08, 2018 | Atlanta, USA
Materials Science and Engineering
15
th
International Conference and Exhibition on
Applied Crystallography
3
rd
International Conference on
&
Synthetic phase and morphology control over colloidal nickel sulfide nanocrystals
Gozde Barim
University of Southern California, USA
B
inary nickel sulfides exist in a variety of phases and stoichiometries, including NiS
2
, Ni
3
S
4
, α-NiS, β-NiS, Ni
9
S
8
, Ni
7
S
6
and Ni
3
S
2
.
Distinct phases of the binary nickel sulfide system have potential to be used as bifunctional catalysts for water splitting, cathode
materials for lithium-ion batteries, absorber layers for solar cells, hydrodesulfurization catalysts, or supercapacitors. However, the
complicated nature of the Ni–S phase diagram makes the solution synthesis of phase-pure colloidal nanocrystals challenging. In
this presentation, the phase- and morphology-controlled solution synthesis of colloidal nickel sulfide nanocrystals is demonstrated.
Nanocrystals of Ni
3
S
4
, α-NiS, β-NiS, Ni
9
S
8
and Ni
3
S
2
can be independently prepared by tuning key synthetic parameters of S:Ni
precursor ratio, capping ligand, reaction time and temperature. S:Ni ratio and temperature influences the phase of nanocrystals, a
phase transformation from cubic Ni
3
S
4
to hexagonal α-NiS and then rhombohedral β-NiS with increasing S:Ni ratios and temperature
is observed. 1-dodecanethiol is shown as an important phase and shape-directing agent. In the presence of 1-dodecanethiol, Ni
9
S
8
nanocrystals with quasi-spherical morphology or Ni
3
S
2
nanoparticles with a multi-pod like morphology can be obtained by using
various disubstituted thioureas are sulfur precursors.
barim@usc.eduRes. Rev. J Mat. Sci. 2018, Volume 6
DOI: 10.4172/2321-6212-C8-036