Preparation And Photocatalytic Properties Of Supported Tetrapyrrole Compounds

Tetrapyrrole compounds,such as phthalocyanines and corroles have a big ring structure with 18?electrons,the NH protons in the molecular center can stable many kinds of metels because of their unique spectral and electrochemical properties.At the same time,all the H atoms around four pyrrole rings can be replaced by the different properties of substituents which build a good platform for design and synthetic with unique optical,electrical and magnetic properties of new compounds.The tetrapyrrole compounds become the research hotpot in different fileds,such as material,position and properties of the substituents provide a powerful opportunity to tune chemical,chemistry and physics.However,the high aggregation tendency casused by the big?system greatly hamper their potential applications as catalysts.In order to expand the applications of tetrapyrrole compounds,a series of novel catalysts were prepared by tetrapyrrole compounds chemically or physically grafted onto the surface of carbon nanotubes or titanium dioxide.Acid black 1?AB1?,rhodamine B?RhB?and methyl orange?MO?were selected as representative organic pollutants to demonstrate the photocatalytic performance of the prepared photocatalysts under visible light.In addition,the possible photocatalytic degradation mechanism was also discussed in detail.The main studies are as follows:1?Preparation and photocatalytic properties of nanocomposites mixed-ZnPc-fMWCNT and linked-ZnPc-fMWCNTThe nanoarchitectonic composites mixed-ZnPc-fMWCNT and linked-ZnPc-fMWCNT were prepared through tetra-[?-?p-amino?benzyloxyl]phthalocyanine Zinc?II??ZnPc?mixed and covalently linked to multiwalled carbon nanotubes?MWCNTs?,respectively.Various spectroscopic methods were used to identify the nanocomposites formed between ZnPc and MWCNTs whether by?-?interaction or by covalent linking.The nanocomposites displayed excellent photocatalytic performance of photodegradation with Rhodamine B?RhB?,and the photodegradation efficiency was 94%for linked-ZnPc-fMWCNT and 83%for mixed-ZnPc-fMWCNT within 3 hours irradiation.The repetition test revealed that both nanocomposites have excellent stability and recyclability,and then they are promising candidates as eco-friendly photocatalysts for degradation of organic dyes in aqueous environments.2?Preparation and photocatalytic properties of chemically modified amino phthalocyanine-GPTMS/TiO2A novel functional material,Zinc?II?tetra-[?-?p-amino?benzyloxyl]phthalocyanine?ZnPc?upon covalent integration with glycidoxypropyltrimethoxy silane modified TiO₂?GPTMS/TiO₂?was prepared here for the first time in order to improve the visible photocatalytic activity of TiO₂.The photocatalytic property of obtained ZnPc-GPTMS/TiO₂ hybrid was investigated by carrying out the photodegradation of di-anionic azo dye Acid Black 1?AB1?in aqueous solution under visible light irradiation.The results revealed that the ZnPc-GPTMS/TiO₂ hybrid photocatalyst greatly enhanced the photodegradation efficiency compared to that of the pure TiO₂.Particularly,0.2 wt%ZnPc-GPTMS/TiO₂ photocatalyst showed the highest photocatalytic activity with a degradation ratio of 95.4%of AB 1 after 120min irradiation.The photocatalytic mechanism was proposed based on the result of the experiment in the end.3?Preparation and photocatalytic performance of corrole doped TiO2The nanocomposite H₃[Cor?Cl-Ph?₂?OH-Ph?]/TiO₂ was achieved by H₃[Cor?Cl-Ph?₂?OH-Ph?]loaded on the surface of TiO₂ with dehydration reaction between the phenolic hydroxyl of the corrole and the titanium hydroxyl on the surface of TiO₂ and was fully characterized here by means of methods.The photocatalytic property of H₃[Cor?Cl-Ph?₂?OH-Ph?]/TiO₂ towards the photodegradation of methyl orange?MO?was comparatively assessed.The results revealed that the nanocomposite H₃[Cor?Cl-Ph?₂?OH-Ph?]/TiO₂ showed much higher photodegradation efficiency than pure TiO₂,the photodegradation efficiency of MO is 69.4%for nanocomposite H₃[Cor?Cl-Ph?₂?OH-Ph?]/TiO₂ while it is only 39.0%for the pure39.0%within 2.5 h irradiation.The photocatalytic mechanism was proposed based on the results of the capturing experiment.