Iron-included mesoporous silica thin slice as adsorbent and Fenton-like catalyst for the adsorption and degradation of dye in wastewater

Abstract An FeOx included SiO2 thin slice was prepared by ball milling the mixture of silica xerogel and iron (III) acetylacetonate, followed by uniaxial pressing and calcination. The slice is highly mesoporous. The incorporated iron is not crystalline but exists as isolated Fe3+ ions (30%), Fex3+Oy clusters (9%) and bulky form of FeOx (61%). The relative contents of Fe2+ and Fe3+ are 39.1 and 60.9%. The sample removed lowly concentered (20 mg/L) methylene blue (MB) from water via adsorption. It showed a very efficient removal (99.94%) of MB with a concentration of 1000 mg/L via Fenton-like catalytic degradation, contrast to a removal of 38.34% by the iron-free slice. It is evidenced that 83.09% of the dye molecules was degraded into CO2 and H2O and 6.40% into small molecules by the active iron species in the slice. Compared with traditional adsorbents and catalysts, the thin slice is easy to prepare, use and collect.