Microwave-enhanced catalytic degradation of methylene blue by porous MFe2O4 (M = Mn, Co) nanocomposites: Pathways and mechanisms
Microwave-enhanced catalytic degradation of methylene blue by porous MFe2O4 (M = Mn, Co) nanocomposites: Pathways and mechanisms
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DOI：
10.1016/j.seppur.2014.07.049
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发表时间：
2014-10
影响因子：
8.6
通讯作者：
Shu-ting Liu;Ao-Bo Zhang;Kangkang Yan;Y. Ye;Xuegang Chen
中科院分区：
文献类型：
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作者：
Shu-ting Liu;Ao-Bo Zhang;Kangkang Yan;Y. Ye;Xuegang Chen
开发快速有效的去除水中染料的方法已受到全球关注。以船体为原料，制备了具有高比表面积和孔容的多孔MnFe 2 O 4（RMN）和多孔CoFe 2 O 4纳米复合材料（RCN），研究了它们对亚甲基蓝（MB）的催化降解作用及其降解机理。在微波加热条件下，RMN和RCN对亚甲基蓝的选择性加热和催化降解活性的增强，使其对亚甲基蓝的去除率显著提高。MB的去除符合准二级动力学模型。去除率随样品投加量、微波输出功率和初始pH值的增大而增大。微波处理后，pH值趋于中性。无论是吸附还是微波处理，MB分子中的二甲氨基（包括甲基）更容易被纳米复合材料中的铁氧体纳米颗粒降解。根据得到的MB、NO3-和SO 42-的浓度，MB的最大去除率达到99.7%，其中超过46.8%的分子被完全降解。该研究为微波强化铁氧体处理碱性染料的降解行为和机理提供了重要信息，也为去除水溶液中有机污染物提供了一种潜在的快速有效的方法。
Developing rapid and effective methods to remove dyes from water has gained global concerns. In this study, we prepared porous MnFe2O4(RMN) and porous CoFe2O4nanocomposite (RCN) with high BET surface area and pore volume using rice hull, and investigated their catalytic degradation and degradation mechanisms for methylene blue (MB). Under microwave heating, the MB removal by RMN and RCN was accelerated and enhanced significantly due to the selective heating and enhanced catalytic degradation activities. The MB removal fits pseudo-second-order model. The removal rate increases with sample dosage, microwave output power, and initial pH value. The resulting pH value was inclined to neutral after microwave treatment. The dimethylamino including methyl groups in MB molecule are easier and prior to be degraded by ferrite nanoparticles in the nanocomposites during either adsorption or microwave treatments. According to the resulting concentrations of MB, NO3−, and SO42−, the maximum MB removal achieved 99.7%, among which more than 46.8% molecules were completely degraded. This study provided essential information on the degradation behavior and mechanism of basic dyes by microwave-enhanced ferrite treatments and also supplied a potential rapid and effective method to remove organic contaminants from aqueous solutions.