Method for preparing nano-composite by controllable deposition of silver atoms on surface of nano-oxide

Abstract

The invention discloses a method for preparing a nano-composite by controllable deposition of silver atoms on the surface of nano-oxide. The nano-composite is composed of transition metal or rare-earth oxide and silver cluster which is deposited and grows on the surface of transition metal or rare-earth oxide. The method is realized through an organic amine improved silver mirror reaction. That is to say, silver atoms generated by reducing a silver amine complex with aldehyde are controllably deposited on the surface of nano-oxide. By using organic amine as a complexing agent, the silver mirror reaction can be carried out in a mild and controllable way. The method comprises the following specific steps: dispersing surfactant-wrapped nano-oxide into an organic solvent to obtain a system A; dissolving silver salt and organic amine in an organic solvent to obtain a silver amine complex solution B; and adding the solution B into the system A, adding an excessive amount of aldehyde and keeping for 1-30 h, precipitating a product with ethanol, centrifuging and washing to obtain the nano-composite. By changing addition amount of the silver source and effectively controlling reaction time, size of silver species in the nano-composite is controlled within 0.3-3 nm.

Description

technical field [0001] The invention belongs to the field of nanotechnology, and in particular relates to a method for preparing nanocomposites by controllable deposition of silver atoms on the surface of nanometer oxides. technical background [0002] In recent years, nanocomposites formed by transition metals and their nanoclusters uniformly distributed on the surface of nanoscale oxides have attracted widespread attention as a very valuable nanomaterial. Especially in the field of catalysis, it has very good catalytic performance as a catalyst. Compared with the traditional metal salt impregnation method, an obvious advantage of the in-situ reduction deposition method is that it can effectively control the entire reduction deposition process, so that the size of the metal particles loaded on the surface of the oxide can be controlled and distributed uniformly, and the impregnation method can be avoided. Aggregation occurs during high temperature pyrolysis, making size co...

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Problems solved by technology

However, in this method, the photoinduced electronic excitation is generally completed quickly at the beginning of the synthesis process, making it difficult to effectively control the entire reduction process, so the size of the silver particles obtained is often large (≧3nm), and this method is limited to titanium dioxide with optoelectronic properties. materials, other transition metal and rare earth metal oxides with poor photosensitivity cannot be used