The activation of hematite for the catalytic hydrogen peroxide degradation of Methylene Blue

The activation of hematite was conducted via thermal treatment in a hydrogen atmosphere to form zero-valent iron (ZVI). The physicochemical properties of ZVI before and after reaction were characterized via X-ray diffraction and X-ray photoelectron spectroscopy. The effects of ZVI dose, H2O2 concentration, initial pH, reaction temperature, initial MB concentration, and different anions on the degradation of MB were examined. The degradation mechanism was elucidated by combining the analysis of total organic carbon (TOC) removal, electron paramagnetic resonance, and UV-Vis. When the ZVI dose is 69 mg/L with an initial pH of 3.0, approximately 100% of color was removed, and a 47% TOC degradation was achieved. Furthermore, after ZVI was cycled seven times, the decolorization efficiency had only a slight decrease, which implies an excellent stability. Fe2+ released by ZVI is important and was essential in the catalytic H2O2 degradation of MB. The experimental data showed that H2O2 was catalyzed by activated hematite in the Fenton process. This observation indicated that the activation of hematite to prepare ZVI was a promising method and had a considerable application value and potential for the MB degradation.