Preparation And Photocatalytic Activity Of Perylene Diimide Composition Photocatalysts

Perylene diimide?PTCDI?was a wide band gap n-type organic semiconductor material which had attracted wide attention nowadays.It had strong electron-attracting effect,high electron affinity and unique optical and electronic properties,and had high application prospects.However,the application of perylene imide semiconductor materials in photocatalysis is limited due to its irregular appearance and high electron-hole recombination rate.The monomolecular PTCDI was assembled by H-aggregation to form a two-dimensional lamellar structure,which solved the problems of low regularity and uneven morphology.PTCDI@TiO₂ hybrid materials with visible light activity were prepared by mechanical ball milling.The formation of electron transport channel between PTCDI and TiO₂ improves the separation efficiency of electron-hole and further improves the photocatalytic activity of the composite.The results showed that the degradation rates of phenol and 2,4-dichlorophenol by PTCDI@TiO₂ under visible light were 82%and 100%respectively,which were 2.3 and 3.2 times higher than that of monomer PTCDI.The degradation efficiency and stability of the complexes were higher than those of other catalysts.On the basis of this study,the mechanism of photocatalysis Fenton synergistic treatment of pollutants is further discussed.The composite catalyst?-Fe₂O₃@PTCDI was prepared by ultrasonic and calcination of ferric nitrate and PTCDI.The?-Fe₂O₃ nanoparticles were fixed on the PTCDI nanosheets to form a heterogeneous structure.The results show that the degradation rate of phenol by the composite catalyst is 4.3 and 5.5 times higher than that of the two monomers under the synergistic effect of Fenton-photocatalysis under visible light.After three cycles,the degradation efficiency of the composite catalyst can still reach 92%.Experiments show that the electrons generated by illumination can be quickly transferred to Fe³⁺,which can generate Fe²⁺.At the same time,Fe²⁺participates in Fenton reaction,catalyzes the formation of hydroxyl radicals in hydrogen peroxide,and speeds up the Fenton reaction,which synergistically improves the degradation efficiency of organic pollutants.Figure 36;Table 3;Reference 96...