Preparation method of shape-controllable nano silver core/mesoporous silicon dioxide shell structure

Abstract

The invention provides a preparation method of a shape-controllable nano silver core / mesoporous silicon dioxide shell structure. The preparation method comprises the following steps of: (1) preparing shape-controllable nano silver particles; (2) modifying the surfaces of the nano silver particles: adding 15ml of isopropanol into an aqueous solution of the nano silver particles, then adding 0.1-0.5g of CTAB (cetyltrimethylammonium bromide) powder, then adding deionized water, stirring for 15-30 minutes or performing ultrasonic treatment for 1-20 minutes; (3) adding 100 micro-liters of 0.1mol / L sodium hydroxide solution and 30-100 micro-liters of tetraethyl orthosilicate into the solution obtained in the step (2), and stirring for 3 hours; (4) removing a template agent to form a mesoporous structure: drying the solution obtained in the step (3) at 100 DEG C, and performing high-temperature calcination for 5 hours at 550 DEG C. The preparation method provided by the invention is simple in process, the used raw materials are low in price and easily-available, the cost is low, and toxic chemicals are not used during preparation. The shape-controllable nano silver core / mesoporous silicon dioxide shell structure prepared by the method provided by the invention is used as a catalyst applied to catalytic reactions, and has wide development application prospects in high-temperature catalytic reactions.

Description

technical field [0001] The invention relates to the intersection field of nanomaterials and biotechnology, in particular to a method for preparing a shape-controllable nano-silver core / mesoporous silica shell structure. Background technique [0002] Nano-metal particles are widely used in the field of optoelectronics, sensing and catalysis due to their unique photoelectric properties, catalytic properties, dielectric properties, and sensing properties. These properties are not only related to the size of metal particles, but also the morphology of nano-metals is one of the important influencing factors. This is due to the fact that different active crystal planes have an important impact on the properties of nanometals. For example, the {100} facets of cubic silver nanoparticles have higher catalytic activity than the {111} facets of nanosheets in the catalytic oxidation of styrene [see Xu, R.; Wang, D.; Zhang, J.; Li, Y. ., Shape-Dependent Catalytic Activity of Silver Nan...

AI Technical Summary

Problems solved by technology

There are many reports on the preparation of nano-metal particles with different shapes, including spheres, cubes, octahedrons, nanorods, nano-disks, nano-triangular prisms, etc. [see Tao A.; Sinsermsuksaku P.; Yang P., Polyhedral, Silver Nanocrystals with Distinct Scattering Signatures, Angew. Chem. Int. Ed. 2006, 45, 4597–4601 and Jin R.; Cao Y.; Mirkin C.; Kelly K.; Schatz G.; Zheng J., Science 2001, 294, 1901 -1903], and thermal stability and chemical stability are the key factors of catalytic reaction efficiency, but often need high-temperature reaction in catalytic reaction, and nano-metal particle reunites easily in high-temperature reaction, and seriously affects catalytic efficiency

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