| The microscopic particles involved in photocatalytic reactions were mainly electrons and photons,and the modification of a single semiconductor was mainly at the regulation of electrons but rarely involved the field of photons.Increasing the utilization of sunlight and quantum conversion efficiency in an all-round way would be possible if the photocatalytic materials were able to regulate the photons and electrons simultaneously.Photonic crystals were characteristics of manipulating the propagation of photons.Inspired by it,this dissertation bulit the tradition.al photocatalytic materials into photonic crystals that possessed both photonic band gap and electronic band gap,and then the photonic crystals were treated with further modification.We deeply explored the structure-function relationship of these novel photocatalysts.In this dissertation,the morphologies,crystal phrase structures,surface states and optical absorption properties of the photonic crystals photocatalysts were characterized in detail by using a series of characterization methods.Furthermore,electron spin resonance,photoelectrochemical method and scavenger experiment were introduced to investigate the reaction mechanisms.The main conclusions and innovations of this article were as follows:(1)Highly ordered ZnO PCs were prepared by the liquid infiltration method and were further modified by photoreduction to obtain Ag/ZnO PCs composites.The photodegradation reaction rate of RhB of Ag/ZnO PCs with photonic crystals bandgap at 541 nm was more than 2.8 times higher than that of Ag/ZnO NPs,which could be attributed to the synergistic effect of its unique photonic crystal structure,slow photon effects and the electron sink effect of the Ag NPs.(2)CuS/ZnO PCs composites were fabricated by the modification of ZnO PCs through successive ion layer absorption and reaction technology.The photodegradation reaction rate of RhB of CuS/ZnO PCs with photonic crystals bandgap at 532 nm was more than 2.4 times higher than that of CuS/ZnO NPs and the photocatalytic activity remained above 90%after six rounds of experimentation,which could be ascribed to the fact that the p-n junction formed by CuS and ZnO could effectively promote the separation of photo-generated carriers and increase the light absorption efficiency.In addition,the unique structure of photonic crystal could promote mass transfer and light capture.(3)Based on the idea of modifying the low mechanical strength of the photonic crystal framework,the SiC/ZnO photonic crystal composites were fabricated by adding different amounts of SiC powder to the precursor,and the SiC was coated with ZnO on the framework structure.The introduction of SiC could not only enhance the mechanical strength of the photonic crystals framework,but also improve the photocatalyitc degradation activity of ZnO PCs.(4)When the photonic band gap of the photonic crystal matched the characteristic absorption peaks of the dyes,the slow photon effect would enhance the light absorption of the materials and the sensitization of the dyes,thereby increasing the photocatalytic efficiency.The research in this dissertation was mainly based on the research of ZnO photonic crystals,and ZnO photonic crystals were used to prepare composites with heterostructures for further modification of the materials.The solar energy utilization rate and quantum conversion efficiency of materials were effectively increased through the regulation of electrons and photons,providing new ideas for the subsequent development and multifaceted applications of photonic crystals. |
