Optical and structural characteristics of ZnO nanopowders for different preparation methods

¹Departamento de Metalurgia e Materiais, Escola Politécnica da USP, Universidade de São Paulo-USP, Av. Prof. Mello Moraes 2463, São Paulo-SP, 05508-030, Brazil

²UnB Gama-FGA, Universidade de Brasília-UnB, Área Especial de Indústria Projeção A, Brasília-DF, 72444-240, Brazil

Adv. Mater. Lett., 2017, 8 (12), pp 1193-1198

DOI: 10.5185/amlett.2017.1581

Publication Date (Web): Sep 08, 2017

Copyright © IAAM-VBRI Press

E-mail: gleciavs@gmail.com, drapilar@gmail.com

Abstract

Zinc oxide (ZnO) nanoparticles (NPs) were synthesized by different methods known as Pechini and Sol-Gel. It was observed during the experiments significant differences comparing these methods as: particle size, time applied, crystallinity and chemical residues generated by-products. The NPs were analysed by X-ray diffraction (XRD), ultraviolet-visible (UV-Vis.) absorption and Raman spectroscopy techniques. X-Ray Difractograms showed peaks corresponding to hexagonal wurtzite crystalline structure. It was observed that NPs obtained by the Pechini showed better homogeneity and crystallinity; these presented average size of 115 nm. The NPs produced by Sol-Gel method showed crystallites with smaller average size of 8 nm. The band gap energy (Eg) obtained using UV-Vis for ZnO NPs synthesized by Pechini was 3.39 eV. Still, the results for Sol-Gel method with 5 and 10 hours of reactions were 3.53 eV and 3.55 eV respectively. Raman data obtained by Pechini and Sol-Gel Methods showed characteristics peaks. The obtained data confirmed the ZnO phase samples and the proportional relationship to the enlargement with the intensity of peaks E_{2 High ˜} 438 cm^-1, as evidenced by literature. These results lead to the applicability of both NPs in optoelectronic and fluorescent applications. 

Keywords

ZnO, nanoparticles, pechini method, sol-gel method.