Synthesis And Property Of Functional Hybrid Nanomaterials From Metal-organic Frameworks

Both functional materials and metal-organic frameworks?MOFs?have wide application potentials in many fields,such as biomedicine,energy and environment.It is known that the physical and chemical properties of materials are closely related to their size,morphology and composition.For taking advantages of metal-organic frameworks as well as conferring metal-organic frameworks with functionality,development of novel synthesis strategies is of great significance.Based on metal-organic coordination chemistry?biomineralization and cation exchange reaction,this dissertation focuses on design and synthesis of novel hybrid nanomaterials as well as their functional properties and further applications in biomedicine,energy and environment.The details were summarized as follows:Firstly,a facile synthesis method based on metal-organic coordination chemistry has been developed for synthesis of pH-responsive nanocapsules.The preparation procedure involved the synthesis of ZIF-8 templates,the formation of metal-organic thin films on the surface of templates and finally the mild removal of templates.ZIF-8were used as sacrificial templates for the immobilization of anticancer drugs with a high loading efficiency.Uniform coating are obtained by a single coordination-enabled assembly step,eliminating the need for multiple steps.In addition,the Fe³⁺-catechol complex film enabled a pH-responsive controlled release of anticancer drugs.Due to their easy preparation and the properties of stimuli-responsive,the metal-organic nanocapsules are expected to have extensive applications in the area of nanoreactors and targeted drug delivery processes.Secondly,a facile biosynthesis approach to synthesize ultrafine,uniform and well-distribution Ag and Au nanoparticles?NPs?by taking the synergy of protein-induced biomineralization and space-confined effect of MOFs is developed.Due to the narrow size distribution?1.2±0.3 nm?and homogeneous spatial distribution of AgNPs,the as-synthesized Ag/Lysozyme@ZIF-8 NPs exhibit remarkably elevated catalytic activity for hydrogen production from alkaline formaldehyde solution relative to AgNPs synthesized through the conventional non-space-confined method.Thirdly,a facile method for the synthesis of well-defined hollow metal-organic frameworks is developed based on cation exchange reaction.Due to their hollow structures and tailoring physical and chemical properties,such hollow MOF exhibit a highly efficienet catalytic activity toward CO₂ conversion under mild condition.Impressively,the catalytic ability of the hollow MOF is demonstrated in a recyclable manner in the cycloaddition of CO₂ with epoxides.