کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5144752 1496869 2017 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Facile, high yield ultrasound mediated protocol for ZnO hierarchical structures synthesis: Formation mechanism, optical and photocatalytic properties
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی (عمومی)
پیش نمایش صفحه اول مقاله
Facile, high yield ultrasound mediated protocol for ZnO hierarchical structures synthesis: Formation mechanism, optical and photocatalytic properties
چکیده انگلیسی


- ZnO structures were obtained by an ultrasound method in absence of additives.
- The irradiation time manipulates the defect content and morphology.
- The ZnO presents high photocatalytic activities.

Hierarchical flowers-like zinc oxide structures have been successfully obtained by a simple and fast ultrasound-assisted method performed in a ordinary ultrasonic bath using an ammonia solution and zinc acetate, in the absence of any surfactant or template. The composition, structure, crystallinity, morphology and optical properties of the materials obtained at different ultrasound irradiation times were characterized by infrared, UV-Vis and photoluminescence spectroscopy, X-ray diffraction, scanning and transmission electron microscopy investigations. It was proved that the ultrasound irradiation time manipulates both the defect content (implicit the photoluminescent properties) and morphology of the ZnO materials: shorter irradiation times leads to the synthesis of high-defected ZnO structures of flower morphology with triangular-shaped petals, while higher irradiation times favours the formation of low-defected ZnO structures with tipped rod-like petals. A plausible growth mechanism of the architectures that implies aggregation via oriented attachment followed by an Ostwald ripening is advanced based on these results. The ZnO flower-like structures present high photocatalytic activities, a total phenol mineralization being registered in the case of visible light experiments. Electron-spin resonance measurements demonstrate the generation of reactive oxygen species, namely hydroxyl radicals but also C centred radicals adducts derived most probable from the residual acetate adsorbed on ZnO surface.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Ultrasonics Sonochemistry - Volume 36, May 2017, Pages 326-335
نویسندگان
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