Magnetically separable nanocomposites with photocatalytic activity under visible light for the selective transformation of biomass-derived platform molecules

Novel magnetically separable TiO2-guanidine-(Ni,Co)Fe2O4 nanomaterials were prepared and characterised by a series of techniques including XRD, SEM, TEM, N-2 physisorption as well as XPS and subsequently tested for their photocatalytic activities in the selective transformation of malic acid in aqueous solution. The modification with guanidine, which remarkably decreases the band gap of the metal oxide, was found to have a significant effect in the photocatalytic activity of the materials under visible light, showing a remarkably superior activity to that of the commercial Degussa P25. These materials are also envisaged to have interesting photocatalytic activities under sunlight.