Natural Clay Supported Hemin As a Biomimetic Catalyst to Degrade 2,4,6-Trichlorophenol.

Natural clay supported hemin as a biomimetic catalyst to degrade 2,4,6-trichlorophenol Peroxidase is a family of widely distributed enzymes in natural environment. In the presence of hydrogen peroxide, peroxidase can catalyze the oxidation of many organic contaminants. To mimic the peroxidase activity, our study used smectite clay as the template to immobilize hemin, which is considered as the active site of peroxidase. Both FTIR and XRD spectra indicated that hemin formed strong interaction with exchangeable cations in clay interlayer and UV-Vis spectra showed that hemin remains as the reactive monomer form when it is associated with clay. The loading of hemin by clay is as high as 9% by weight. The synthesized bioconjugate showed great catalytic activity when 2,4,6-trichlorophenol was used as the model compound. The degradation rate is strongly dependent on the hemin loading and system pH. 2,4,6-trichlorophenol (0.1 M) can be completely degraded within 1h when pH is adjusted to 3. Our results demonstrate that the unique structure of natural smectite clay can stabilize the hemin molecule to prevent the self-dimerization of hemin, and the intercalation of hemin in the interlayer could protect the molecule from the attack of radicals formed in the reactions.