Preparation And Performance Study Of Conjugated Microporous Polymer With Photocatalytic Activity

Solar energy occupies a pivotal position in the future development of new energy because of the inexhaustible,clean and pollution-free,renewable,etc.And hydrogen energy can be generally considered to be an ideal,non-polluting,high combustion value and the combustion,the product will not cause any pollution to the environment,therefore,hydrogen energy development is one of the ideal ways to solve the energy crisis and environmental pollution in the future.The core issue of hydrogen energy technology development is how to achieve large-scale and low cost for hydrogen production.In many hydrogen development tools and means,the use of solar energy photocatalytic water splitting is the most ideal and promising technology,known as the "21st century's dream technology".While the development of efficient,inexpensive and practical new photocatalyst is the key to the realization of this technology,has become one of the current research hotspot in the field.The core problem of photocatalytic hydrogen production from water currently is mainly low quantum yield and weak response to the visible light,to solve these problems is the choice and preparation of special structure and performance photocatalyst.The development of novel and highly efficient of visible light response photocatalyst not only has significant application value in environment and energy,but also promotes the materials,chemistry,physics,environment and energy interdisciplinary,and has spawned new major frontier research fields.Therefore,the study of hydrogen production by solar photocatalytic water splitting is not only a major demand for the implementation of sustainable development strategy in China,but also reflects the current development trend of interdisciplinary.In this paper,the molecular design and preparation strategy of the conjugated microporous polymers and the performance of photocatalytic hydrogen evolution from water were carried out.A novel conjugated microporous polymer photocatalysts with multi-component and multi-stage structure were designed to introduce the structural primers with electron and hole transport ability into the polymer backbone.To prepare the conjugated microporous polymer photocatalyst which could effectively transport and separate the photo-generated electron-hole,copolymerizing the narrow bandgap elements in the macromolecule skeleton could effectively absorb the visible light.To systematically studying the factors of the photocatalytic performance of the conjugated microporous polymer photocatalysts,such as structure,specific surface area and band gap,etc.And a new method for the preparation of conjugated microporous polymers with photocatalytic hydrogen evolution under visible light was constructed.The main research contents include the following four aspects:(1)Tunable synthesis of CMP photocatalysts with specific surface areaChoosing planar rigid and space distortion conjugate structure as the precursor,functional modification with polyfunctional reactive groups,synthetic series by copolymerization with different structure unit conjugate microporous polymers,research the specific surface area of the conjugate microporous polymers by the different structure units,polymerization and crosslinking degree,by adjusting the basic building blocks in order to realize the effective control of the specific surface area of the conjugated polymer microporous,study the photocatalytic performance of conjugated polymer microporous photocatalysts witch contains different structural unit.(2)Tunable synthesis of CMPs with photogenerated electrons and hole transporting abilityPhotocatalytic reaction occurs on the surface of the materials,thus improve the photogenerated electrons and holes quickly move to the surface of the photocatalyst materials and effectively implement the separation of each other,so as to avoid composite electrons and holes are particularly crucial raw.Introducing an electronic transmission capability of heterocyclic compound,such as benzothiazole and thiophene,into the CMPs backbone by chemical copolymerization method to prepared the CMP photocatalysts with electronic transmission capability.Research the photocatalytic performance of CMP photocatalysts different electron properties units.(3)CMP photocatalysts with tunable bandgapsIntroducing the narrow band gap monomers into the polymer frameworks by copolymerization,CMP photocatalysts with narrow bandgap can be prepared to absorb more visible light.By adjusting the ratio of different band gap structure monomers were synthesized different series of polymer under same polymerization condition can absorb the visible light spectrum,realize the preparation of polymerization bandgap macro aspects of effective control,and research the different combinations of band gap structures of polymerization monomers in CMP photocatalysts.(4)Synthesis of strong fluorescent chromophore containing CMPsA novel CMP photocatalyst was synthesized by derivatizing the strong fluorescent chromophores to obtain the multifunctional polymerizable reactive groups.The photosensitive properties of the polymers were changed by the introduction of the fluorescent groups.And research the heterogeneous catalytic oxidation of organic compounds.The series CMP photocatalysts for the synthesis of the above were carried out the photocatalytic hydrogen production from water splitting.The basic structure of the polymers and the specific surface area,with/without electron or hole transport abilities,the optical bandgaps,the sacrificial agent kinds,and wavelength of the light source on the photocatalytic hydrogen production performance were studied.And the CMP photocatalysts recycling activity and life were measurement.