Figure 6

Color removal as a function of (a) persulfate concentration, (b) Fe78Si9B13 dosage, (c) light intensity and (d) UV-Vis spectrum at different time intervals (if not mentioned, the reaction conditions are irradiation intensity: 7.7 μW/cm2, dye concentration: 20 ppm, Fe78Si9B13 dosage: 0.5 g/L, persulfate concentration: 1.0 mM).