Preparation And Performance Study Of Au@ Zeolitic Imidazolate Framework-8 Composite Materials

With the development of research and application of nanomaterials,anisotropic gold nanoparticles have unique physical and chemical properties and can apply to a variety of application fields.In order to prevent the agglomeration of gold nanoparticles,which leads to shorter life and lower performances,the gold nanoparticles can be compounded with metal organic framework to increase its the reaction selectivity and anti-toxicity.In this paper,gold nanosheets were prepared by seedless growth method.Then,ZIF-8 epitaxially grow on gold nanosheets by the post-synthesis of MOFs,and the Au@ZIF-8 composite materials was prepared.The structure and properties of the obtained composite materials are studied.The results show that the morphology of the composite materials with triangular gold nanosheets as the core can be controlled by the optimized materials preparation process.Compared with gold nanosheets,Au@ZIF-8 composite materials has better light absorption in ultraviolet region and weaker absorption in visible region.The composite materials has a good thermal stability within 500?.The gold nanosheets have catalytic activity on the 4-NP reduction by NaBH₄ as reducing agent,and the reaction can be almost completed in⁵5min.The catalytic activity of Au@ZIF-8 composite materials is affected,and that can only make about 1/4 p-nitrophenol reacted in 80min.Au@Ag core-shell structure materials can be obtained by reducing silver nitrate with gold nanosheets as the core by a simple solution method.The Au@Ag@ZIF-8composite materials can be prepared by the post-synthesis of MOFs.The results show that the composite materials with Au@Ag as the core can be controlled by the optimized materials preparation process.Au@Ag has a good absorption of visible light and has almost no absorption of light at the wavelength of 325nm.Au@Ag@ZIF-8 has a stronger light absorption than Au@Ag in the wavelength range of 200-800nm and a stronger absorbance in ultraviolet region.The Au@Ag@ZIF-8 composite materials has a better thermal stability within 550?,and the thermal stability is slightly higher than Au@ZIF-8.Au@Ag has a good catalytic activity on the 4-NP reduction by NaBH₄ as reducing agent.The reduction reaction can be completed in¹0min,while the catalytic activity of Au@Ag@ZIF-8 composite materials is affected.Moreover,the catalytic effect is similar to Au@ZIF-8 composite materials.Figure 18 table 4 reference 80...