| Phenolic compounds as an important of chemical industry basic raw material is used invarious industrial fabrication, coking, gas, chemical and other industries, which will producelarge volumes of wastewater, is a kind of typical chemical contaminants. Since a wide sourceof phenolic wastewater has the characteristic of large quantities and hazards, its processingtechnology has aroused wide concern. Conventional phenolic wastewater treatment methodsnot only costly, time-consuming, complicated operation, but also cause secondary pollution[1].Enzyme with the advantages of high catalytic efficiency, mild conditions and environmentallyfriendly but it difficult to obtain, easier to inactivation, expensive, so it is limited in practicalapplications, thus mimic enzyme research has aroused widespread. Natural Hemin is an ironporphyrin compounds, presents in the blood of animals widely, as Mimetic Peroxidase iswidely used in chemical kinetics[2]and analytical chemistry[3]and other aspects of theresearch. Since natural hemins absorb in UV chloride, limiting its application in wastewatertreatment areas. In order to improving its catalytic activity, considering affect the catalyticactivity of porphyrin, we synthesized three different supported metal porphyrin biomimeticcatalysts, and its properties were characterized and evaluated.Firstly preparation of the catalyst: influencing the catalytic activity of metalloporphyrinsfactors include axial ligand, central metal ion and the peripheral substituents, the firstchoosing natural hemin as raw materials synthesized a five-coordinate imidazole ligandscomplexes; then using natural hemin as raw materials, which through the process of ironremoval esterification, ester solution and bonding metal ions, prepared for different metalporphyrins; Finally using meso-tetrakis (4-sulfonatopheny) porphyrin synthesizedmeso-tetrakis (4-sulfonatopheny) porphyrin iron. As metalloporphyrins was reunion in watereasily, resulting in decreased the activity of catalytic, so that we synthesized the cellulosemagnetic microspheres carrier, and choosing cyanuric chloride as crosslinking agent loadeddifferent porphyrin synthesis on the surface of carrier, we synthesized of three differentsupported metal porphyrin biomimetic catalysts.Secondly characterization of the catalyst: Light absorption property of the photocatalystwas identified by the UV-vis spectrometer of U-3900H.The IR spectra of the photocatalystwere recorded by the FT-IR Spectrometer of NICOLET370. The surface morphology of thesample was observed by the TEM microscope of Philips Tacnai G2F20. The content oforganic compound on the surface of carrier was measured by TG method using athermogravimetric analyzer of TGA Q50. The hysteresis loop was measured by VSMmagnetometer of MPMS-XL-7.Finally performance evaluation of the catalyst: The photocatalytic activities of thecatalysts were evaluated by degradation of hydroquinone under the visible light irradiation.The results showed that under the conditions of the amount of axial-ligand biomimetic catalyst0.2g L-1, initial concentration of HQ20mg L-1, pH=6and reaction time6h, thedegradation rate of HQ reached96.97%. The degradation rate was still up more than88%after eight-cycle photocatalytic test; The activity order of catalyst with different central metalion is zinc porphyrin> cobaltporphyrin> nickel porphyrin> copper porphyrin, when the loadtype zinc porphyrin biomimetic catalyst dosage of20mg, HQ initial concentration of20mg L-1, pH=6.5and the reaction time was6h, the degradation rate of the water HQ95.52%,repeated use of8times, the degradation rate is still up86.32%; Meso-tetrakis(4-sulfonatopheny) porphyrin iron imitation enzyme catalyst dosage of20mg, HQ initialconcentration of20mg L-1, pH=6and the reaction time was6h, the degradation rate of92.27%, repeated use of8times, the degradation rate dropped to76.77%. Simultaneously westudied the different photocatalytic degradation mechanism of HQ with different catalyst. |
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