Ionic liquid based microemulsion method for the fabrication of poly(methyl methacrylate)–TiO2 nanocomposite as a highly efficient visible light photocatalyst

Abstract

A series of visible light-responsive poly(methyl methacrylate) (PMMA)/TiO₂/IL nanocomposite transparent films, with different loading of TiO₂ nanoparticles, were facilely prepared using an ionic liquid-in-oil microemulsion system. The microemulsion system was containing methyl methacrylate monomer as continues phase, 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim][BF₄]) as dispersant phase, Triton X-100 as surfactant and 1-butanol as co-surfactant. TiO₂ nanoparticles were dispersed into the microemulsion system, and then the oil phase was polymerized by a benzoyl peroxide initiator. Techniques such as UV-vis diffuse reflectance spectra (DRS), TEM, FTIR, XRD, FE-SEM and TGA were used to characterize the resulting nanocomposite. Methylene blue (MB) dye was used as a model pollutant to study the photocatalytic activity of this novel type of PMMA/TiO₂/IL nanocomposite. As an interesting result, it is found that the prepared nanocomposite exhibit excellent photocatalytic activity under visible light irradiation and considerably higher photocurrents than bare TiO₂. Moreover, influence of various operational parameters such as pH, the amount of loaded TiO₂ nanoparticles and recycling of the photocatalyst on the degradation reaction was investigated in detail.