Influence of structural disorder on the photocatalytic properties of ZnS nanocrystals prepared by the one-pot solvothermal approach
Título del documento: Influence of structural disorder on the photocatalytic properties of ZnS nanocrystals prepared by the one-pot solvothermal approach
Revista: Ecletica quimica
Base de datos:
Número de sistema: 000552419
ISSN: 0100-4670
Autores: 1
2
3
4
5
Instituciones: 1Federal University of Technology of Paraná, Laboratory of Nanotechnology and Computational Chemistry, Londrina, Brazil.,
2Federal University of Rio Grande do Norte, Department of Materials Engineering, Natal, Brazil. São Paulo State University, Modeling and Molecular Simulation Group, Bauru, Brazil.,
3São Paulo State University, Modeling and Molecular Simulation Group, Bauru, Brazil.,
4Brazilian Center of Physical Research, Rio de Janeiro, Brazil.,
5Federal University of Technology of Paraná, Laboratory of Nanotechnology and Computational Chemistry, Londrina, Brazil. State University of Londrina, Post-Graduation Program in Chemistry, Londrina, Brazil.,
Año:
Volumen: 47
Número: 3
Paginación: 17-31
País: Brasil
Idioma: Inglés
Resumen en inglés This study focuses on the impact of the sulfur vacancies on the photocatalytic response of the ZnS nanocrystals synthesized by solvothermal method varying the concentration of zinc acetate/thiourea precursors. XRD patterns show that these samples have a hexagonal structure with different degrees of crystallinity, varying the crystallite size from 2.48 to 2.85 nm. The UV-Vis data reveals an absorption peak (at about 320 nm) characteristic of ZnS nanocrystals. As a result, a decrease in the bandgap value of these materials was observed from 3.78 to 3.62 eV. In principle, a comparison of these results and theoretical calculations reveals the formation of intermediate levels inside the bandgap due to structural polarization. These findings also corroborate the zeta potential measured for these samples, evidenced by an increase of positive charge of ZnS surfaces. Also, the low Miller-index surfaces, such as (100), (110) and (0001), were investigated by periodic density functional theory calculations, in nice agreement with the experimental data. A photocatalysis mechanism was investigated and confirmed the formation of reactive oxygen species.
Keyword: ZnS,
density functional theory,
solvothermal processing,
photocatalysis properties,
electronic structure
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