One-step microwave preparation method for bimetal/carbon layered composite sphere

Abstract

The invention discloses a bimetal / carbon layered composite sphere and a simple and quick preparation method for the same. The preparation method is based on merits of microwave heating, and includes that mixed liquor containing metal ions {including positive ions such as [Ag(NH<3>)<2>]<+>, Pd<2+> and Au<+> and negative ions such as MCl<n>(wherein the M represents Au, Pd and Pt)} with different electric charges is used as a precursor, and different types of metal selectively are grown inside and outside a carbon sphere simultaneously, so that the bimetal carbon-doped layered composite sphere with nano-particles can be prepared. The bimetal / carbon layered composite sphere and the preparation method have the advantages that an integral preparation procedure only takes 2-10 minutes, and reaction parameters are adjusted, so that the sizes, the number density and the positions of the metal nano-particles can be controlled; the shortcoming of difficulty in growing more than two types of metal nano-particles inside a preliminarily prepared carbon sphere can be overcome, and the constraint that usually only alloy can be generated via co-reduction of mixed metal ions under the condition of traditional heating is broken through; devices applied in the preparation method are simple, operation is easy, the controllability is good, and the preparation method can be particularly popularized to controllable preparation for other bimetal doped multilayer composite materials with nano-particles.

Description

technical field [0001] The invention relates to bimetallic / carbon layered composite spheres used in the fields of optics, catalysis, and biosensing, and a simple and fast preparation method thereof, in particular to the realization of two metals or metal complex ions with different charges on carbon by one-step microwave The interior and the surface are simultaneously reduced to obtain a bimetal / carbon composite sphere with a layered structure. Background technique [0002] Doping metal nanoparticles into the interior or surface of the spherical matrix can obtain catalytic, magnetic, electrical, optical and other properties different from metal nanoparticles and their random aggregates. The small size effect, collective effect, and metal-matrix synergy of nanoparticles have important effects on the performance improvement. Especially in the aspect of catalysis, the micropores of the matrix material have a confinement effect on the nanoparticles, which can enhance the cataly...

AI Technical Summary

Problems solved by technology

The doping of two kinds of metal particles can be achieved by using a two-step method (that is, obtaining composite spheres of carbon-coated metal nanoparticles first, and then depositing a second metal on the surface of the spheres), but the steps are cumbersome, the products are not uniform, and each carbon Usually only one metal nanoparticle can be wrapped inside the sphere

It has not been reported that two or more metal nanoparticles can be grown simultaneously inside and outside the matrix through one-step reaction to obtain a multilayer composite structure.

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