Study On The Structure And Properties Of Linear Porphyrin Polymers

Porphyrin is a kind of excellent photosensitizer,which can effectively absorb visible light and near-infrared light in sunlight.At the same time,it also has excellent ability to generate active oxygen,and has been widely developed as a homogeneous photocatalyst for photocatalytic degradation of organic dyes.However,since the porphyrin is easily aggregated into a multimer,and the catalytic activity of porphyrin is lowered.In addition,porphyrin as a small molecule catalyst,is difficult to separate and recover after photocatalytic degradation reaction.It is easy to cause secondary pollution.These shortcomings limit the application of porphyrin in the field of catalysis.In order to solve these problems,one of the effective ways is to change the small molecular into polymer as heterogeneous catalyst.In this thesis,5,15-p-?4-carboxyphenyl?-10,20-diphenylporphyrin?H₂DiCPp? was first synthesized.Two linear structure polymers were prepared through polycondensation by H₂DiCPp and4,6-diaminoresorcinol hydrochloride and benzidine,namely polyphenylporphyrin benzobisoxazole and polyphenylporphyrin benzamide.They are used as a heterogeneous photocatalyst for photocatalytic degradation of organic dyes.Under visible light irradiation,the photocatalytic degradation rate of RhB,including polyphenylporphyrin benzobisoxazole under hydrogen peroxide,can reach 98% within 150min.At the same time,the heterogeneous photocatalyst polyphenylporphyrin benzobisoxazole and polyphenylporphyrin benzamide are insoluble in water and will not cause secondary pollution to water bodies.After four cycles of use,they are still highly efficient for photocatalytic degradation of RhB.In addition,the photocatalyst mechanism was initially explored by adding active oxygen scavengers into the degradation system.