Construction And Application Of Functional Metal-Organic Gels Materials

Metal organic gels（MOG）have attracted much attention in recent years as a porous material with a novel structure and excellent properties.MOGs are supramolecular organic colloids formed by the combination of metal ions and organic ligands.The introduction of metal ions brings many unique properties that hold great promise for applications in the fields of adsorption,catalysis and analytical sensing.The downside is the structural uncertainty caused by too many influencing factors in the synthesis process of MOG,therefore,the rational design for the preparation of functional metal organogel composites with novel functions and high stability remains a great challenge.In this paper,functional metal organogel composites were synthesised using aluminium-based metal organogels as the matrix and introducing different functional materials,and the practical applications of the composites in the fields of oxidative desulphurisation of fuel oil and photocatalytic degradation of pollutants were investigated.The main parts include the following:The second chapter of the thesis utilises aluminium metal organics with a high specific surface area and multi-level pore structure as a carrier for the homogeneous dispersion of Keggin-structured phosphomolybdic acid（PMA）in order to prepare well-dispersed and highly loaded multi-acid based metal organics PMA@MOX（Al）catalysts.The microstructure of the catalyst was characterised by XRD,SEM-EDX,FT-IR,N₂ adsorption-desorption isotherms and XPS.The effects of PMA loading,catalyst dosage and ultrasonic power on the performance of oxidative desulphurisation were investigated.The results show that60%-PMA@MOX（Al）has the best catalytic activity with a desulphurisation rate of 98.6%,which can be maintained at more than 90%even after seven repetitions.In addition,kinetic studies of different desulphurisation methods showed that the unique thermal and cavitation effects of ultrasound can effectively improve the efficiency of oxidative desulphurisation.In the third chapter of the thesis,CdS QDs@MOX（Al）heterojunction photocatalysts were prepared using the gel-limited method by dispersing CdS quantum dots（CdS QDs）in the metal organogel MOX（Al）.The compositional structure and interfacial charge transport efficiency of the samples were characterized and analyzed by XRD,TEM,XPS,N₂adsorption-desorption isotherm curves,UV-Vis DRS and EIS,and the catalytic activity and mechanism of the synergistic degradation of norfloxacin（NF）and reduced Cr（VI）under visible light were explored.The results showed that 1.0-CdS QDs@MOX（Al）exhibited excellent photocatalytic activity for the NF/Cr（VI）complex pollutant system,with the degradation process conforming to a pseudo primary kinetic model and the apparent rate constants k being 6.1（8.5）and 5.3（3.5）times higher than those of pure MOX（Al）and CdS,respectively.The photocatalytic efficiency of CdS QDs@MOX（Al）for the NF/Cr（VI）complex pollutant system was significantly higher compared to the single pollutant system.Active species capture experiments confirmed that h⁺and·O₂^-were the main active species,and the enhanced photocatalytic activity was mainly attributed to the Type-II heterostructure formed between MOX（Al）and CdS QDs,which accelerated the effective separation and transfer of photogenerated charges at the interface of the heterostructure.