Degradation of Rhodamine B by Fe Heteropoly Acid Hydrogen Peroxide Under Visible Light

A light Fenton like system PW11O39Fe(III)(H2O)4- (PW11Fe/H2O) was constructed using Kegn type iron instead of heteropolyanion PW11Fe as the visible light active component, and was used for visible light catalytic degradation of model pollutant Rhodamine B (RhB). At the same time, the effects of H2O2 concentration, PW11Fe concentration, initial RhB concentration and pH value of solution on the visible light catalytic degradation rate of RhB were investigated, and the kinetic properties of RhB photocatalytic degradation were discussed. The experimental results showed that the system composed of 0.6mmol·L-1. PW11Fe and 4 mmol·L-1H2O2 had the best photocatalytic degradation effect on RhB when the pH of the solution was 4.5. RhB with 0.01mmol·L reacted for 60 minutes under 250W metal halide lamp irradiation, achieving a degradation rate of 100%. The reaction lasted for 240 minutes, and the total organic carbon (TOC) removal rate was about 48%. The hydroxyl radical quenching and electron paramagnetic resonance (EPR) experiments showed that the PW11Fe/H2O2 system produced hydroxyl radicals under visible light irradiation, which led to the rapid degradation of RhB. The apparent Reaction rate constant of the degradation reaction was 6.2 mmol·L-1·min-1.