of hydrazine hydrate to En play key roles in the shape evolution of
h-NiSe crystals. The addition of NH4Cl decreases the nucleation
rate of h-NiSe and the diffusion rate of growth resources, while
the adsorption of ethylenediamine at {001} facets inhibits the
crystal growth of hexagonal NiSe crystals in o0014 directions,
thus leading to the systematical shape evolution of nickel selenides.
Future work is in progress to gain further insight into the
performances and applications of these materials. This simple
solvothermal approach with the assistances of mixed solvents
and electrolyte may be extended to the shape-controlled
synthesis of other metal chalcogenides with unique shapes and
structures.