Impact of surfactant ratios on mesostructured MnFe2O4 nanocomposites and their photocatalytic performance

Abstract Synthesis of mesoporous MnFe2O4 nanocomposites employing a simple one-pot approach of manganese acetate with ferric nitrate at varying surfactant F127 triblock copolymer molar ratios from 0.0075 to 0.020 was conducted, and their impacts on the physical properties, morphology, crystallinity, and photocatalytic performance were investigated. TEM images of the synthesized mesoporous MnFe2O4 nanocomposites exhibit a quasi-spherical structure with 15-20 nm diameters. The lattice spacing of the MnFe2O4 plane (311) was determined by ∼ 0.256 nm, implying the construction of the cubic MnFe2O4 lattice structure. Interestingly, the obtained mesoporous MnFe2O4 nanocomposites have a large surface area of 227 m2/g for the first time. The total pore volume and average pore diameter were measured ∼6.0 nm and 0.33 cm3/g, respectively. The photocatalytic performance of the mesoporous MnFe2O4 nanocomposites for degradation of ciprofloxacin (CIP) was boosted from 50% to 100% by increasing surfactant F127 molar ratios from 0.0075 to 0.020. The photodegradation rate of the synthesized photocatalyst at 0.020 surfactant F127 molar ratio is higher two times than that of the synthesized one at 0.0075 molar ratio. Such high photocatalytic performance of mesoporous MnFe2O4 nanocomposite at high surfactant F127 molar ratio as compared with other samples might be referred to some effects like generation high •OH concentration, reduction of light scattering as a result of large pore volume and high surface area, or a rapid diffusion of the CIP to the active sites through the mesoporous structure.