Structure-directing coordination template effect of ethylenediamine in formations of ZnS and ZnSe nanocrystallites via solvothermal route

ZnS and ZnSe precursors (ZnS.0.5en and ZnSe.0.5en, en = ethylenediamine) were prepared via a solvothermal process using ethylenediamine as solvent. Phase-pure hexagonal wurtzite ZnS and ZnSe products were obtained by annealing the precursors in argon stream at temperatures above 350 degreesC. The role of ethylenediamine as a structure-directing coordination molecular template responsible for the morphologies of the annealed products was discussed. This work provided further insights into the solvent coordination molecular template (SCMT) mechanism previously proposed to explain the growth mechanism of CdE (E = S, Se, Te) nanorods in ethylenediamine (Inorg. Chem. 1999, 38, 1382). The as-prepared precursors as well as the annealed products were characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), infrared absorbance spectroscopy (IR), thermogravimetric analysis (TGA), X-ray fluorescence (XRF) analysis, and combustion analysis for C, N, H contents.