PVP-assisted synthesis of rod-like ZnO photocatalyst for photodegradation of reactive red (RR141) and Congo red (CR) azo dyes
| Autor: | Jidapa Watcharakitti, Suwat Nanan, Tammanoon Chankhanittha |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
010302 applied physics
Materials science Condensed Matter Physics Photochemistry 01 natural sciences Atomic and Molecular Physics and Optics Electronic Optical and Magnetic Materials law.invention Congo red Catalysis Crystallinity chemistry.chemical_compound Reaction rate constant chemistry law 0103 physical sciences Photocatalysis Calcination Electrical and Electronic Engineering Photodegradation Wurtzite crystal structure |
| Zdroj: | Journal of Materials Science: Materials in Electronics. 30:17804-17819 |
| ISSN: | 1573-482X 0957-4522 |
| DOI: | 10.1007/s10854-019-02132-z |
| Popis: | A ZnO photocatalyst has been synthesized via a hydrothermal method using polyvinylpyrrolidone (PVP) as a capping agent. The ZnO catalyst shows hexagonal wurtzite structure with a rod-like microstructure (0.58 μm × 2.47 μm, from TEM) due to the assembly of many crystallites. An excitonic peak found in photoluminescence (PL) spectrum at 367 nm indicates a significant improvement of sample crystallinity after calcination. The catalyst showed a remarkable photocatalytic efficiency of 100% toward degradation of two azo dyes. High crystallinity together with low electron–hole recombination rate found in the catalyst promoted its enhanced photodegradation efficiency. The degradation reaction showed first-order kinetics with a rate constant of 0.0186 min−1. Both electron and superoxide anion radical play the most important role involved in photodegradation of the dye. The second majority comes from hydroxyl radical (OH·) which also made a huge contribution toward photodegradation of the dye. The ZnO catalyst remained stable after three cycles of use. The catalyst showed approximately the same efficiency even after the third run. This work demonstrates the promising potential of ZnO photocatalyst for environmental remediation. |
| Databáze: | OpenAIRE |
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