Fe/sponge structure peanut shell carbon composite preparation for efficient Fenton oxidation crystal violet.

In order to obtain super synergy effect between adsorption and Fenton oxidation for crystal violet (CV) removement from water, in this study, Fe modified on a sponge structure peanut shell carbon (Fe/SPSC) nanocomposite was successfully synthesized by a wet impregnation method. In the Fe/SPSC sample, the prepared peanut shell carbon had a sponge-like structure, (002) crystal plane of graphite crystallite, and Fe/SPSC composite coexisted FeO and FeO crystalline, which could adsorb and enrich crystal violet molecule, decrease the concentration of CV solution rapidly. And also SPSC could do better for electrons transfer and further promote CV oxidation degradation. The removal efficiency results showed that the 7% Fe/SPSC (500 °C, 2 h) had the best CV removal activity. The composite prepared under the optimum conditions is 2.0 g/L, 0.1 mL 30% HO, pH = 7.0, 300 mg/L crystal violet water solution, and the CV degradation rate can reach 95.5%, and the CV degradation amount for Fe/SPSC was 143.25 mg/g. It was confirmed that hydroxyl radicals (•OH) is the active center of Fenton oxidation degradation reaction. XPS results showed that Fe, O, and C elements coexist in the 7% Fe/SPSC composite, and N element content increases after the reaction. Remarkable synergies between adsorption and Fenton oxidation, which could make Fe/SPSC, have quick CV abatement ability. The possible systematic effect mechanism of adsorption and Fenton-oxidation CV was also supplied. The present system has advantages on high CV dye degradation performance, no other Fe sludge formation, short reaction time, and better catalyst reusability.