Azam Sobhani, M. Salavati‐Niasari
2014
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Influential Citations
65
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Journal
Superlattices and Microstructures
Abstract
Abstract A series of nickel selenides (NiSe and NiSe 2 ) has been successfully synthesized from the reaction of SeCl 4 with NiCl 2 ⋅6H 2 O in the presence of cetyltrimethyl ammonium bromide (CTAB) as surfactant and hydrazine hydrate (N 2 H 4 ⋅H 2 O) as reductant at 180 °C for 12 h through a simple hydrothermal method. The morphology, phase structure and composition of Ni x Se y can be controlled by adjusting the Ni/Se ratio of the raw materials, the quantity of reductant, the reaction temperature and so forth. The products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy - dispersive X-ray spectroscopy (EDS) analysis. It was found that when the ratio of Ni/Se is 1:1 or 3:2, flower-like assemblies of NiSe nanosheets are formed, at 180 °C for 12 h. When the ratio of Ni/Se is 1:2 at 180 °C, the products are found to be the mixture of hexagonal NiSe and cubic NiSe 2 . With decrease of nickel content in molar ratio of 1:2 (Ni:Se), nanospheres are agglomerated and microstructures are formed. With the reaction temperature decreasing from 180 °C to 120 °C, we reach pure NiSe 2 nanoparticles. The formation mechanism of the nickel selenides has been investigated in detail by means of XRD and SEM analyses.