Preparation Technology Of Noble Metal-Zinc Based Metal Organic Framework Composite Nanoparticles

Nobel metal nanomaterials have been widely used in suface plasmonics,sensing,catalysis,and biomeducine because of their excellent physical and chemical properties.However,the agglomerate of nanoparticles which is due to the high surface energy shows adverse effect for their performance.One way to solve this problem is combining the precious metal nanoparticles with porous materials(metal oxides,molecular sieves,activated carbon,etc.)to construct noble meatal/porous material complexes.Metal-organic frameworks were a new type of porous materials,its special properties such as large surface areas,ordered pore structure,pore and surface chemical properties of modulation make it widely used in gas storage and separation,catalysis,sensing,drug delivery and electronic devices.By combining the metal nanoparticles with meta-organic frameworks materials,the new metals-MOFs hybrid nanomaterials were fabricated and which showed very high catalytic activities.Zeolitic imidazolate framework,also known as ZIF-8,are a class of MOFs.Due to their topological structure and MOFs properties,ZIF-8 are being investigated for applications.In this thesis,we present our works on the synthesis and photocatalytic properties of ZIF-8 and its noble metal composite nanoparticles.The main contents include the following parts:1.Study on the synthesis of zinc based MOFs nanostructures with different morphologies in ethylene glycolZinc based metal-organic frameworks(ZIF-8)were successfully synthesized with good stability in ethylene glycol solvent.The as-prepared ZIF-8 nanoparticles have uniform size and good dispersibility.The effects of the concentration of precursor,reaction temperature,surfactant type and concentration on the morphology and size of the product were studied.Meanwhile,the formation process was studied by controlling the reaction time.The result shows that the morphology and size of nanoparticles can be controlled effectively by controlling the reaction conditions.This work provides a new idea for the preparation of zinc based MOFs composite nanoparticles and the construction of noble metal zinc based MOFs composite nanoparticles.2.Preparation technology of Au@ZnO@ZIF-8 core shell composite nano-particles with photocatalytic propertiesA rapid and efficient strategy for the synthesis of Au@ZnO@ZIF-8 core-shell composite nanoparticles with Au@ZnO as core was presented.The experimental result shows that the Au@ZnO@ZIF-8 core-shell composite nanoparticles have good morphology and good dispersibility.By investigating evolution process,the formation mechanism of composite nanoparticles had been deeply studied.The thickness of the shell was changed by adjusting the reaction parameters.What's more,the relationship between the reaction conditions and the product structure was revealed.In this study,the photocatalytic activity of Au@ZnO@ZIF-8 core-shell composite nanoparticles was investigated by the photocatalytic degradation of rhodamine B.The result indicates that the prepared composite nanomaterials have good catalytic properties,which can be expected to be used in the photocatalytic degradation of pollutants,environmental management and protection in the future.