Quantitative investigation into the enhancing utilization efficiency of H2O2 catalyzed by FeOCl under visible light

Abstract

FeOCl was prepared by a partial thermal decomposition method to effectively catalyze hydrogen peroxide under the visible light for the degradation of toxic organic wastewater. The combination of DRS and VB-XPS indicated that FeOCl is a narrow band gap catalyst with visible light absorption capacity (Eg =1.63 eV). The degradation rate constant of RhB in FeOCl/H2O2/Vis system is about 13.4 times that of FeOCl/H2O2 system. Compared to other heterogeneous Photo-Fenton systems, the oxidant utilization efficiency in FeOCl/H2O2/Vis system is higher. In addition, FeOCl has stable Photo-Fenton activity in a wide pH range (3.0–9.0). The content of Fe(II) increased after 5 cycles reaction through the ESR and XPS characterization, which proves that the electron transfer of Fe(III)/Fe(II) was improved during the reaction. After quantitative analysis of the ·OH generated in the reaction, the formation rate of ·OH in FeOCl/H2O2/Vis system is increased about 30% compared with FeOCl/H2O2/dark system. These results indicate that visible light excites FeOCl to generate produces photogenerated electron-hole pairs, accelerating the cycle of Fe(III)/Fe(II), promoting the production rate of ·OH, and enhancing the catalytic efficiency of FeOCl.