The Synthesis And Catalysis Performance Research Of Metal Oxide/Silica Nanocapsules

Compared with traditional materials of larger size,the properties of metal oxide nanomaterial show more superior due to the special size effect of nanomaterial.Therefore,metal oxide nanomaterial can be applied to more aspects.However,in practical application,metal nanomaterial lacks of stability,and it is easy to agglomerate after contacting with each other,resulting in uncontrolled nano-size and the loss of unique properties.In general,in order to overcome these obstacle,nanomaterial is always combined with a stable matrix material to isolate the nanoparticles,there comes that the stability of the nanomaterials is significantly improved.Moreover,among common micro-configurations,nanocapsules have attracted more attention due to their superior high specific surface area and high adsorption capacity,which can gain better application performance thanothers.Therefore,the research on the silicananocapsule has certain significance in scientific research and industrial application.In this paper,the hard-template method and the self-catalyst effect of APTES to construct Si-O-Si network were combined.The silica nanocapsules loaded with metal nanoparticles were successfully synthesized under near-neutral conditions by selecting appropriate precursor.Two main works are as follow:C nanospheres were prepared as a hard template by hydrothermal carbonization method,meanwhile cobalt bromoacetate was synthesized as a precursor,constructed continuous Si-O-Si network on the surface of the template by APTES and TEOS,then the sample was calcined to obtain Co₃O₄@SiO₂ nano capsules.Finally,the reaction of reducing methyl orange with NaBH₄ was used as template to test the prepared nanocapsules,and the nanocapsules showed good catalytic and cyclic properties.Preparing CoBA₂@SiO₂/C,using the special reaction of Br atoms and Ag⁺ions,Ag⁺is introduced into the shell of nanocapsules,and calcined to form Co₃O₄ and Ag in situ.Ag-Co₃O₄@SiO₂ nanocapsules were finally synthesized.The reaction of reducing methyl orange with NaBH₄ was still used as template,and the material exhibited better catalytic and cyclic properties.