Enhancing Fenton-like catalytic efficiency of Bi2WO6 by iodine doping for pollutant degradation

Introducing reductive species into heterogeneous catalysts can improve their catalytic efficiency in Fenton-like processes. Iodide ions (I − ), a typical reductive species with good reducibility, might enhance the catalytic performance of H 2 O 2 activation when doped in heterogeneous catalysts. In this study, the iodine-doped Bi 2 WO 6 (I X -Bi 2 WO 6 ) nanosheets were synthesized with a facile hydrothermal method and used to activate H 2 O 2 to degrade bisphenol A (BPA). Compared with Bi 2 WO 6 , which was almost inactive, the I X -Bi 2 WO 6 exhibited great improvement for BPA degradation. Among the fabricated catalysts, the I 0.50 -Bi 2 WO 6 with an iodine content of 0.50 mmol was found to be most effective and could work efficiently in a wide pH range from 4.0 to 10.0. Moreover, with a low consumption of H 2 O 2 (H 2 O 2 : pollutant molar ratio = 10:1), 78% BPA was degraded within 10 min at initial pH 7.0. Unlike the conventional H 2 O 2 activation mechanism, the direct electron transfer was verified to be the main mechanism for the BPA degradation based on the results of electron paramagnetic resonance (EPR) analysis, radical quenching, and electrochemical experiments in this work. Furthermore, the activation of H 2 O 2 by iodine-doped BiVO 4 and Bi 2 MoO 6 was also conducted to validate the applicability of such an iodine doping approach. These results indicate that the introduction of reductive species I − is a promising and effective method to develop highly efficient Bi-based catalysts for H 2 O 2 activation.