The Construction And Photocatalytic Properties Study Of Copper-Based Metal-Organic Frameworks

The synthesis of valuable organic chemicals using solar energy has been a popular but challenging research topic in the field of photocatalysis.Metal-organic frameworks（MOFs）,a class of porous crystalline materials constructed by metal ions or clusters（SBUs）and organic linkers,hold great promises in the field of heterogeneous photocatalysis.Metal ions or clusters and ligands in the framework can act as independent catalytic centers to improve catalytic activity and stability.Moreover,the tunable nature and porous structure of MOFs materials allow the fixation of functional groups and photocatalysts into one framework to further prolongation of the excited-state lifetime and overcome restrictions in homogeneous catalytic systems.Furthermore,the clearly defined MOFs structure has great advantages in understanding the structure-activity relationship,allowing us to further explore the mechanism of photocatalysis.copper（I）has excellent stability and excellent optical activity.In addition,the persistent radical effect（PRE）of copper and its versatile redox properties make it promising for photocatalytic applications.Based on this,a variety of copper-based MOFs were constructed in this paper,combining the excellent characteristics of copper and the structural features of MOFs to prevent ineffective inter-or intramolecular fluorescence quenching and further extend the excited state lifetime,which has a broad prospect in photocatalytic applications.Details of the research are as follows:（1）Two new MOFs（Cu-Tpxa-1 and Cu-Tpxa-2）were prepared by a solvothermal method,and their basic photophysical and chemical properties were characterized to explore the differences in the photoelectrochemical properties of the two structurally different MOFs.Cu-Tpxa-1 and Cu-Tpxa-2 combined photocatalysis and copper catalysis for decarboxylative radical cyanation reaction.The differences between the two structurally different MOFs in the catalytic process were demonstrated by a series of experiments such as fluorescence quenching,which allowed us to further explore the structure-activity relationship and the photocatalytic mechanism.The new multiphase catalytic approach optimizes the redox performance and excited state lifetime,which provides a new idea to explore the photocatalytic mechanism.（2）A metal-organic framework material（Cu-Pys）of binuclear copper was constructed by a layered diffusion method as a highly active catalytic center for light-driven hydrogen production.The high catalytic efficiency can be attributed to the synergistic catalytic effect between the two copper ions,i.e.,one can act as a catalytic center to bind and activate the H₂O molecule,and the other can act as an auxiliary catalytic site to promote the breaking of the HO-H bond and enhance the efficiency of photocatalytic hydrogen production.It provides a new idea for exploring efficient and stable non-homogeneous catalysts for hydrogen production and has a broad application in solar photocatalytic hydrogen production.