Magnetic TiO2-graphene composite as a high-performance and recyclable platform for efficient photocatalytic removal of herbicides from water

• Published in: Journal of hazardous materials Vol. 252-253; pp. 115 - 122
• Main Authors: Tang, Yanhong, Zhang, Gan, Liu, Chengbin, Luo, Shenglian, Xu, Xiangli, Chen, Liang, Wang, Bogu
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 15.05.2013; Elsevier
• Subjects: 2,4-Dichlorophenoxyacetic Acid - chemistry; Applied sciences; Catalysis; Catalytic reactions; Chemical engineering; Chemistry; Escherichia coli - drug effects; Escherichia coli - growth & development; Exact sciences and technology; General and physical chemistry; Graphene-TiO2; Graphite - chemistry; Graphite - radiation effects; Herbicide removal; Herbicides - chemistry; Herbicides - toxicity; Magnetic Phenomena; Magnetic separation; Magnetite Nanoparticles - chemistry; Magnetite Nanoparticles - radiation effects; Magnetite Nanoparticles - ultrastructure; Microscopy, Electron, Scanning; Microscopy, Electron, Transmission; Photocatalyst; Photochemical Processes; Pollution; Reactors; Recycling; Reusability; Silicon Dioxide - chemistry; Silicon Dioxide - radiation effects; Sunlight; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; Titanium - chemistry; Titanium - radiation effects; Water Pollutants, Chemical - chemistry; Water Pollutants, Chemical - toxicity; Water Purification - methods; Herbicide removal; Reusability; Magnetic separation; Photocatalyst; Graphene-TiO2; Sonication; Pollutant behavior; Toxicity; Photocatalysis; Pesticides; Adsorption capacity; Herbicide; Composite material; Design; Pollutant; Graphene-TiO; Light absorption; Titanium oxide; Solar radiation; Ultrasound; Catalyst; Photochemical degradation
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2013.02.053

A new magnetic TiO2-graphene hybrid photocatalyst is prepared and acts as a high-performance and recyclable platform for efficient photocatalytic removal of herbicides from water. [Display omitted] ► A magnetically separable TiO2-graphene photocatalyst is carefully designed. ► The catalyst exhibited almost 100% photocatalytic removal of 2,4-D from water. ► The photocatalyst is easily recovered with excellent reusability. ► After being laid aside for one year the catalyst still kept 95.6% removal of 2,4-D. ► 2,4-D in real wastewater could be efficiently removed. A new photocatalyst, magnetic TiO2-graphene, was designed and facilely produced by combining sol–gel and assembling processes. Taking advantages of graphene and TiO2, the catalyst exhibited strong light absorption in the visible region and high adsorption capacity to organic pollutants, resulting in almost 100% photocatalytic removal efficiency of typical herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) from water under simulated solar light irradiation, far higher than 33% on commercial P25. Toxicity assessment indicates the total decomposition of the original substrate. Furthermore, the catalyst can be rapidly recovered with highly stable photocatalytic performance. After 8 successive cycles, the removal efficiency of 2,4-D maintained 97.7%, and particularly, 99.1% 2,4-D removal efficiency came back at the ninth recycle when the catalyst was re-treated by ultrasonication. Moreover, even after being laid aside for one year the catalyst still kept the 2,4-D removal efficiency as high as 95.6%. For practical application, the photocatalytic also demonstrated high removal efficiencies of herbicide 2,4-D. The photocatalyst is a promising platform for removing herbicide pollutants from water.