Fe-based Fenton-like catalysts for water treatment: Preparation, characterization and modification

Abstract

Fenton reaction based on hydroxyl radicals (▪) is effective for environment remediation. Nevertheless, the conventional Fenton reaction has several disadvantages, such as working at acidic pH, producing iron-containing sludge, and the difficulty in catalysts reuse. Fenton-like reaction using solid catalysts rather than Fe2+ has received increasing attention. To date, Fe-based catalysts have received increasing attention due to their earth abundance, good biocompatibility, comparatively low toxicity and ready availability, it is necessary to review the current status of Fenton-like catalysts. In this review, the recent advances in Fe-based Fenton-like catalysts were systematically analyzed and summarized. Firstly, the various preparation methods were introduced, including template-free methods (precipitation, sol gel, impregnation, hydrothermal, thermal, and others) and template-based methods (hard-templating method and soft-templating method); then, the characterization techniques for Fe-based catalysts were summarized, such as X-ray diffraction (XRD), Brunauer, Emmett and Teller (BET), SEM (scanning electron microscopy)/TEM (transmission electron microscopy)/HRTEM (high-resolution TEM), FTIR (Fourier transform infrared spectroscopy)/Raman, XPS (X-ray photoelectron spectroscopy), 57Fe Mössbauer spectroscopy etc.; thirdly, some important conventional Fe-based catalysts were introduced, including iron oxides and oxyhydroxides, zero-valent iron (ZVI) and iron disulfide and oxychloride; fourthly, the modification strategies of Fe-based catalysts were discussed, such as microstructure controlling, introduction of support materials, construction of core-shell structure and incorporation of new metal-containing component; Finally, concluding remarks were given and the future perspectives for further study were discussed. This review will provide important information to further advance the development and application of Fe-based catalysts for water treatment.