Photocatalytic Degradation Of Aqueous Phenolic Compounds By Magnetic Nanocomposite γ-Fe₂O₃@TS-1

A novel heterophoto-Fenton catalyst y-Fe2O3@TS-1was prepared. This catalyst can take full advantage of UV-light, increase the efficiency of catalytic decomposition of H2O2and be recycled to avoid second pollution to environment. Phenolic compounds with the feature of strong toxicity, bioaccumulation and the difficult to biodegrade, threaten the ecological environment and human health seriously. y-Fe2O3@TS-1was used in the degradation of phenolic compounds successfully and the result is satisfying. The research in this paper involves there parts:1. Magnetic core was introduced into the synthesis system of TS-1, and magnetic nanocomposite y-Fe2O3@TS-1was synthesized by dry gel conversion technique. y-Fe2O3@TS-1was characterized by XRD, UV-Vis, SEM and TEM technique.2. y-Fe2O3@TS-1was used in the degradation of4-chlorophenol (4-CP) in simulated wastewater. The effects of reaction conditions such as the dosage of H2O2, initial pH, the dosage of catalyst, reaction temperature, initial4-CP concentration, and the condition of light illumination was studied in terms of chemical oxygen demand (COD) removal. Under the optimum reaction condition,100%COD removal can be achieved after90min. y-Fe2O3@TS-1have a highly effective catalytic activity, and almost remain the original catalytic activity after magnetic recycling. The separation and recovery problem of nanosized TS-1and nanocomposites are resolved.3. Magnetic materials with different amount of magnetic core were researched on the degradation of4-CP. The results show that a moderate amount of magnetic core is beneficial to the degradation of4-CP, and TS-1and magnetic core have a synergistic effect on the degradation of4-CP.4. The degradation mechanism of4-CP in UV/Fenton-like system was discussed. The degradation reaction of4-CP basically conforms to pseudo-first-order kinetics under the optimum reaction condition. The intermediate products in the process of degradation are detected. It is speculated that the degradation pathway can be divided into adsorption, dechlorination, hydroxylation and cleavage of the benzene ring, and the main products are CO2, FbO and chloride ion.