Enhanced photocatalytic activity of Bi2Fe4O9 catalysts with EDTA modification

The degradation of methylene orange (MO) dye was carried out by using sol–gel derived Bi2Fe4O9 nanoparticles under the visible light irradiation with the addition of ethylenediaminetetraacetic acid (EDTA) and hydrogen peroxide (H2O2). The photocatalytic reaction can be termed a kind of photo-Fenton-like process, in which EDTA, H2O2 and visible light irradiation work together to improve the degradation rate of Bi2Fe4O9 catalysts. In the process of photocatalytic reaction, only 50 and 84 % MO removal could be achieved without the addition of EDTA; however, the MO removal could achieve about 74 and 99 % with 0.4 mmol/L of EDTA for irradiation time of 0.5 and 2 h, respectively. The variation of the FT-IR spectra evidences the surface modification effects of EDTA on Bi2Fe4O9 crystallites.