Synthesis and characterization of ZnZr composites for the photocatalytic degradation of phenolic molecules: addition effect of ZrO2over hydrozincite Zn5(OH)6(CO3)2
| Autor: | R. Pérez-Hernández, Francisco Tzompantzi, C.E. Santolalla-Vargas, Verónica De la Luz Tlapaya, Clara Tzompantzi-Flores, Ricardo Gómez, J.C. Castillo-Rodríguez |
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| Rok vydání: | 2019 |
| Předmět: |
Renewable Energy
Sustainability and the Environment Chemistry Scanning electron microscope General Chemical Engineering Organic Chemistry 02 engineering and technology 010501 environmental sciences 021001 nanoscience & nanotechnology 01 natural sciences Pollution Inorganic Chemistry chemistry.chemical_compound Fuel Technology X-ray photoelectron spectroscopy Specific surface area Phenol Diffuse reflection Fourier transform infrared spectroscopy Composite material Hydrozincite 0210 nano-technology Photodegradation Waste Management and Disposal 0105 earth and related environmental sciences Biotechnology |
| Zdroj: | Journal of Chemical Technology & Biotechnology. 94:3428-3439 |
| ISSN: | 1097-4660 0268-2575 |
| Popis: | BACKGROUND: The composite materials ZrO₂/Zn₅(OH)₆(CO₃)₂ were prepared in only one step by chemical co‐precipitation and thermal hydrolysis of urea. ZrO₂ was added at 5, 8 and 10 mol%. The samples were dried at 80 °C and characterized by adsorption–desorption of N₂ isotherms, X‐ray diffraction (XRD) and scanning electron microscopy (SEM) techniques, and diffuse reflectance (DRS), UV–visible, Fourier‐transform infrared (FTIR) and X‐ray photoelectron (XPS) spectroscopies. The materials were assessed in the photodegradation of phenol and polychlorinated phenolic molecules under UV‐light irradiation. The possible mechanism was discussed from studies that corroborated or discarded the formation of the species •OH, •O₂⁻ and h⁺. RESULTS: The addition of ZrO₂ to Zn₅(OH)₆(CO₃)₂ resulted in a composite material with high photoactivity. The material containing 8 mol% of ZrO₂ (ZnZr‐8.0%) was the sample with the best percentages of photodegradation and mineralization. The photodegradation enhancement was achieved partly by an increment in the specific surface area and principally due to localized states originating in the composite interphase which improved charge transfer. XPS study revealed that the ZrO₂ addition increases the oxygen vacancies which enhanced the organic molecule photodegradation via direct hole attack. CONCLUSION: The ZnZr composite system constitutes an excellent alternative for the photodegradation of persistent organic pollutants due to the low cost, high stability and null toxicity of the support Zn₅(OH)₆(CO₃)₂. © 2019 Society of Chemical Industry |
| Databáze: | OpenAIRE |
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