Authors: A. Parra-Palomino, C. Sotomayor, O. Perales-Perez, R. Singhal, P. Voyles and M.S. Tomar
Affilation: University of Puerto Rico, Puerto Rico
Pages: 336 - 339
Keywords: ZnO, monodispersion, nanocrystal
The present research addressed the size-controlled synthesis of ZnO nanocrystals at different temperatures. In order to study systematically the dependence of crystal size with synthesis conditions in ethanol, stable suspensions of these nanocrystals were produced at various temperatures, ranging from 0 0C to 60 0C. XRD characterization of produced materials verified the fast and direct formation of ZnO nanocrystals. In XRD pattern the absence of peaks other than those corresponding to ZnO, suggests well and fast formation of the oxide structure even without aging. Moreover, the XRD patterns show a significant shift in the peaks position, which is evidence of a progressive increment in their lattice parameters. The FT-IR spectra of ZnO crystals synthesized at 00C and aged for different times, show bands at 525cm,1 which is attributed to stretching vibrations of the Zn-O bonds. The bands at 1339, 1404, and 1575 cm-1, are due to the stretching vibration of C=O, C=C and C-H bonds, respectively. The high monodispersity of the 5-8nm ZnO nanocrystals was revealed by HRTEM analysis. Particle growth and aggregation would have been inhibited due to the acetate adsorption. UV-Vis and PL measurements evidenced the continuous growth of the nanocrystals by prolonging aging.