کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1528679 1511985 2014 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Improvement of the photocatalytic activity of magnetite by Mn-incorporation
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد مواد الکترونیکی، نوری و مغناطیسی
پیش نمایش صفحه اول مقاله
Improvement of the photocatalytic activity of magnetite by Mn-incorporation
چکیده انگلیسی


• Efficiently methylene blue dye discoloration using an Mn doped magnetite catalyst.
• Evidence for isomorphic substitution of Fe2+ by Mn2+ in the octahedral structure.
• Mechanism of the enhanced photocatalysis induced by active Mn sites.
• Importance of the Mn reaction rate constant and effective surface area.

Mn-incorporated Fe3O4 photocatalysts were prepared by a simple co-precipitation method. Photocatalytic discoloration of Methylene Blue (MB) was used to evaluate the performance of these catalysts. The DSC results have shown that the insertion of Mn into Fe3O4 lattice has increased converting Fe3O4 to γ-Fe2O3. This is accompanied by a decrease of surface area and of crystallinity, as detected by XRD. The analysis of the chemical environment by XPS has shown that Mn2+ replaces Fe2+ preferentially in the octahedral sites while Mn3+ replaces Fe3+ of inverse spinel sites. The Mn-incorporated samples were significantly more efficient in MB discoloration assisted by UVA irradiation and H2O2. It was also found that ascorbic acid prevents H2O2 decomposition, by scavenging preferentially OOH radicals produced at Mn sites. Finally, the results reported here can contribute for a better comprehension of the activity of composite catalysts and the design of efficient systems for discoloration of organic pollutants.

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ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Materials Science and Engineering: B - Volume 181, February 2014, Pages 64–69
نویسندگان
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