| The current world economy shows a trend of rapid development,which led to the excessive exploitation and consumption of non-recyclable traditional fossil fuels such as coal,oil and natural gas.The demand for traditional fossil fuels increases rapidly,which leads to the depletion of conventional hydrocarbon fuels as the human is about to face a severe energy crisis.In addition,sulfur dioxide,nitrogen dioxide and carbon dioxide from the combustion of traditional fossil fuels cause serious pollution to the atmospheric environment.Without effective improvement strategies,human beings will faced with the energy crises and environmental problems.However,the general energy sources cannot replace fossil fuels completely and cannot achieve the goal of pollution-free,recyclable neither.Solar energy is an inexhaustible source of energy.So if new strategies can be developed to harness solar energy and It will be a viable option.Recent years have witnessed the emergence of semiconductor photocatalytic materials and photocatalyst that can absorb and utilize sunlight and converted it into chemical energy quickly to produce hydrogen from water splitting.The conversion of solar energy from catalyst to clean and pollution-free hydrogen energy can not only solves solves the problem of environmental pollution caused by the burning of traditional fossil fuels,but also alleviates the energy crisis caused by the rapid consumption of non-renewable fossil fuels.Therefore,the preparation of MOFs/B-CTF-1(?NH2-MIL-125?Ti?/B-CTF-1 and NH2-UiO-66?Zr?/B-CTF-1?and modified by different functional groups COFs?NUS-14-CH3,NUS-14-H,NUS-14-NO2?photocatalysts by chemical modification and covalent bonding were systematically discussed in this paper,as well as the research of the catalysts in the photocatalytic aspect.?1?In this paper,we design and synthesize novel photocatalysts with both catalytic activity and stability.First the terephthalonitrile as raw material,through acid catalyzed reaction and high temperature calcination,to synthesis covalent organic frameworks?2D-CTF-1?,2D-CTF-1 is modified with p-amino-aminobenzoic acid to synthesize benzoic acid-based COFs?B-CTF-1?.After that,the NH2-MIL-125?Ti?was modified by amide-condensation reaction between the amino group at the edge of NH2-MIL-125?Ti?and the carboxyl group on the surface of B-CTF-1 under the action of condensation agent,to connected two separate NH2-MIL-125?Ti?and B-CTF-1 are linked together by an amide bond.Among amide bond?-CONH-?to the benefit of the transfer of photogenerated electrons between the two,as an electronic medium.A series of characterization and experiments showed that when NH2-MIL-125?Ti?of 15wt%was used to bond with B-CTF-1,15TBC heterogeneous photocatalyst showed the best hydrogen production rate(360?mol·h-1·g-1),which was twice as high as that of raw CTF-1.?2?In this paper,COFs?NUS-14-CH3,NUS-14-H,NUS-14-NO2?was synthesized from 2,4,6-triazine?4-aldehyde-phenyl?-1,3,5triazine?TFPT?and p-phenylenediamine?2-nitrop-phenylenediamine,2-methyl p-phenylenediamine?by acid-catalyzed?acetic acid?method.The influence of different electron-donating functional groups on the morphology and photoelectric behavior of COFs is discussed by introducing different electron-donating functional groups into COFs.In this chapter,the characterization of COFs materials with different functionalization shows that the introduction of functional groups with different electron donor capacities significantly changes the morphology of COFs materials.In addition,a series of photoelectric chemical tests?ac impedance,fluorescence,photocurrent,diffuse reflection light absorption?have promoted the introduction of functional groups with strong electron absorption ability to the material's light absorption range,photogenic electron and hole separation efficiency. |
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