The role of counter-ions in crystal morphology, surface structure and photocatalytic activity of ZnO crystals grown onto a substrate
| Autor: | Valmor Roberto Mastelaro, Elson Longo, Ariadne C. Catto, Luís F. da Silva, Osmando F. Lopes, Juan Andrés, Waldir Avansi, Mateus M. Ferrer |
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| Rok vydání: | 2020 |
| Předmět: |
hydrothermal
Photoluminescence Materials science Nanostructure FOTOLUMINESCÊNCIA Scanning electron microscope General Physics and Astronomy chemistry.chemical_element 02 engineering and technology Zinc 010402 general chemistry 01 natural sciences Crystal chemistry.chemical_compound Zinc nitrate nanostructures wulff model hierarchical ZnO Substrate (chemistry) Surfaces and Interfaces General Chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics 0104 chemical sciences Surfaces Coatings and Films chemistry Chemical engineering Photocatalysis 0210 nano-technology photocatalysis crystal morphology |
| Zdroj: | Repositori Universitat Jaume I Universitat Jaume I Repositório Institucional da USP (Biblioteca Digital da Produção Intelectual) Universidade de São Paulo (USP) instacron:USP |
| Popis: | In this contribution, we present an experimental and theoretical investigation of the role of counter-ions in the crystal morphology, surface structure, and photocatalytic activity of hierarchical ZnO nanostructures. The effect of zinc precursor (nitrate, acetate and, sulfate) along the synthesis of ZnO nanostructures grown directly onto a substrate by means of a simple hydrothermal method was analyzed in detail. Scanning electron microscopy images showed a preferential growth of ZnO nanostructures along the c-axis, with a slight reduction in the orientation depending on the choice of the Zn source. Theoretical calculations based on the Wulff theory allowed us to better understand the morphological changes and directly relate the photocatalytic performance at the different exposed surfaces of the as-observed crystal shapes. Our results showed that photocatalytic activities in the discoloration of organic dyes became superior for hierarchical ZnO nanostructures obtained from zinc nitrate. This finding was explained by X-ray photoelectron and photoluminescence spectroscopies, which revealed that in addition to, the attached counter-ions and the abundance of carboxylate groups and organic residuals on ZnO surfaces, the presence of surface defects are determinant to enhance the photocatalytic performance of the material. |
| Databáze: | OpenAIRE |
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