Highly efficient magnetically separable TiO2-graphene oxide supported SrFe_(12)O_(19) for direct sunlight-driven photoactivity

摘要

A highly solar photoactive, magnetically separable, TiO2-graphene oxide supported SrFe_(12)O_(19) (TiO2/GO/ SrFe_(12)O_(19)) photocatalyst was synthesised via the solid reaction of silica (SiO2)-coated SrFe_(12)O_(19) with TiO2 and GO, which were produced by a hydrothermal reaction and Hummer's method, respectively. Several aspects of the material chemistry of the prepared photocatalyst were explored: its crystallite phase, particle size, surface morphology, inorganic elemental composition, adsorption-desorption hysteresis, BET surface area, organic functional group, chemical state of surface, magnetic hysteresis, coercivity (H_ci)), saturation magnetisation (M_s), remanence (M_r), thermal property and visible light absorption analysis. The synthesised TiO2/GO/SrFe_(12)O_(19) exhibited greater ferromagnetic properties (H_(ci): 2103 Oe; M_s: 3.406E~(-3) -emu g~(-1); M_r: l.642E~(-3) emu g~(-2)), which further enhanced its re-usability. The incorporation of GO and SrFe_(12)O_(19) resulted in a drastic reduction in the bandgap energy (1.80 eV). Moreover, this incorporation contributed for the higher visible light absorption. The photoactivity of TiO2/GO/SrFe_(12)O_(19) was evaluated under direct sunlight for the degradation of 2,4-dichlorophenol (2,4-DCP). The degradation over a period of 5 h suggested excellent photoactivity.