Magnetic recoverable MnFe₂O₄ and MnFe₂O₄-graphene hybrid as heterogeneous catalysts of peroxymonosulfate activation for efficient degradation of aqueous organic pollutants

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• 作者：Yunjin Yao^a ; ^c ; ^{yaoyunjin@gmail.com" class="auth_mail} ; Yunmu Cai^a ; Fang Lu^a ; Fengyu Wei^a ; Xiaoyao Wang^a ; Shaobin Wang^b ; ¹ ; ^{shaobin.wang@curtin.edu.au" class="auth_mail}
• 关键词：Peroxymonosulfate ; MnFe2O4 ; Graphene ; Sulfate radical ; Organic pollutant
• 刊名：Journal of Hazardous Materials
• 出版年：15 April, 2014
• 年：2014
• 卷：270
• 期：Complete
• 页码：61-70
• 全文大小：4390 K

文摘

Magnetic iron based materials are generally effective for many catalytic reactions and can be magnetically recovered after application, showing advantages than other metal oxides. In the present work, magnetic MnFe₂O₄ nanoparticle and MnFe₂O₄-reduced graphene oxide (rGO) hybrid were prepared and used as catalysts to activate peroxymonosulfate (PMS) to oxidatively degrade various organic pollutants in water. From a process of chemical deposition and reduction, MnFe₂O₄-rGO hybrids were produced with nanosized MnFe₂O₄ particles (ca. 13.2 nm). It was found that MnFe₂O₄ or MnFe₂O₄-rGO presented high activity in activating PMS to produce sulfate radicals for degradation of organic dyes (Methyl violet, Methyl orange, Methylene blue, Orange II and Rhodamine B) and could be separated with a magnet without any loss. The reaction kinetics, effect of different ion species and Cl^{鈭?/sup> strength, reaction temperature (25-65 掳C), catalytic stability, as well as degradation mechanism were comprehensively studied. The lower activation energy on MnFe₂O₄-rGO (25.7 kJ/mol) justify the higher chemical performance than that of MnFe₂O₄ (31.7 kJ/mol), suggesting that graphene plays a significant role in the enhanced degradation of dyes. More importantly, the as-prepared MnFe₂O₄ and MnFe₂O₄-rGO hybrid exhibited stable performance to remove the organic pollutants in wastewater with easy recycling and good stability by successive degradation experiments.}