학술논문
Annealing effects on the photocatalytic activity of ZnO nanoparticles.
Document Type
Academic Journal
Author
Giraldi TR; Instituto de Ciência e Tecnologia - Unifal, Rodovia José Aurélio Vilela, 11999, Cidade Universitària - Poços de Caldas, MG, Brazil.; Santos GV; Mendonça VR; Ribeiro C; Weber IT
Source
Publisher: American Scientific Publishers Country of Publication: United States NLM ID: 101088195 Publication Model: Print Cited Medium: Print ISSN: 1533-4880 (Print) Linking ISSN: 15334880 NLM ISO Abbreviation: J Nanosci Nanotechnol Subsets: MEDLINE
Subject
Language
English
ISSN
1533-4880
Abstract
This paper describes the development of ZnO nanoparticles by a chemical method, to test them in the photocatalysis of the degradation of textile dyes, using Rhodamine B (RhB) as a probe reaction. The samples were submitted to different heat treatments in order to observe the annealing effects on the photocatalytical properties, surface decontamination and the consequent particle change, in terms of crystallinity. The as-prepared samples (ZOA) correspond to a metastable phase (oxy or hydroxy zinc acetate) and post annealing leads to ZnO crystallization. In spite of the XRD patterns showing only the ZnO phase for heat treatment at 100 degrees C, FTIR data show that carboxylate groups remains attached to the ZnO surface up to 300 degrees C. Up to 300 degrees C the presence of these carboxylate groups, provided by the synthesis method, showed to be more relevant to photoactivity than the specific surface area. At higher temperatures, crystallinity becomes the dominant factor and an increasing of crystallinity favors the photoactivity.