Enhanced Visible-light-driven Photocatalytic Activity of Multiferroic KBiFe2O5 by Adjusting pH Value

Abstract

Multiferroic KBiFe2O5 was successfully prepared by a facile hydrothermal method. Its phase purity and morphology were investigated by powder X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM). The visible-light absorption was confirmed by UV-Vis diffuse reaction spectroscopy (UV-Vis DRS). Effect of pH value on visible-light-driven photocatalytic properties of KBiFe2O5 was evaluated by degrading rhodamine B (RhB) and methyl orange (MO). It can be found that lower pH value contributed to smaller average particle size. The D50 of the sample at pH 7 is about 10 times larger than that at pH 2. Acid condition is beneficial to the dispersion of KBiFe2O5 nanoparticles, which leads to an enhanced photocatalytic performance. Photocatalytic activity of KBiFe2O5 is significantly improved by decreasing pH value of the solution, which is attributed to the promoted dispersion of catalyst particles in the suspension and the enhanced adsorption of dye molecules on the catalyst surface.