Cobalt ferrite nanoparticles supported on electrospun carbon fiber as a magnetic heterogeneous catalyst for activating peroxymonosulfate

• Published in: Chemosphere (Oxford) 2018-10, Vol.208, p.502-511
• Main Authors: Lin, Kun-Yi Andrew, Yang, Ming-Tong, Lin, Jyun-Ting, Du, Yunchen
• Format: Article
• Language: English
• Subjects: Amaranth; Carbon nanofiber; Cobalt ferrite; Electrospun; Peroxymonosulfate
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2018.05.127

Cobalt ferrite (CF) nanoparticle (NP) represents a promising alternative to Co3O4 NP for peroxymonosulfate (PMS) activation in view of its strong magnetism for easy recovery. As CF NPs in water are prone to agglomerate, a few attempts have been made to immobilize CF NPs on substrates. While carbonaceous supports are more favorable owing to their earth abundancy, the study of carbon-supported CF for PMS activation is limited to graphene-based CF, which, however, requires complicated protocols to prepare. As carbon-supported CF, by straightforward preparation, is still greatly desired, this study aims to employ electrospinning techniques for preparing carbon-supported CF by carbonizing an electrospun CF-embedded polyacrylonitrile (PAN) fiber. After carbonization, the CF-PAN fiber is converted into CF-embedded carbon nanofiber (CF@CNF), which contains well distributed CF NPs, high magnetism and stable carbon support, making CF@CNF a highly promising catalyst for activating PMS. As amaranth decolorization is used as a model reaction, CF@CNF is able to activate PMS for generating sulfate radicals and then decolorize amaranth in water. Amaranth decolorization by CF@CNF-PMS is also substantially facilitated at elevated temperature, and enhanced under the weakly acidic condition. CF@CNF also remains effective to activate PMS even in the presence of salts and surfactants, and re-usable over multiple cycles. Compared to other reported catalysts, CF@CNF also exhibited a much lower Ea value (35.8 kJ/mol) for amaranth decolorization. These features validate that CF@CNF is an advantageous and convenient catalyst for activating PMS. [Display omitted] •Cobalt ferrite@carbon nanofiber (CF@CNF) is prepared via electrospinning techniques.•Magnetic CF@CNF can effectively activate PMS for amaranth decolorization.•CF@CNF exhibits a higher catalytic activity than Co3O4 for activating PMS.•Ea of amaranth decolorization by CF@CNF-PMS is lower than those of other catalysts.•CF@CNF can be also re-used to activate PMS for degradation of Amaranth.