The invention discloses Au@AuPt
alloy nanoparticles and a preparation method of a colloidal dispersion
system, and particularly provides nanoparticles having a preparation method and a controllable reaction process and a preparation method of a colloidal dispersion
system. The method comprises the following steps: preparing a
system A: the system A contains a dispersion
reagent, a gold precursor, a
platinum precursor and a protective agent, wherein the protective agent is
sodium di-n-octyl sulfosuccinate, the gold precursor is HAuCl4, NaAuCl4 or AuCl3, and the
platinum precursor is H2PtCl6 or Na2PtCl6; at
room temperature, adding a
reducer A into the system A while stirring to reduce part of the gold precursor, adding a
reducer B, and continuing stirring at
room temperature until the reaction is complete, thereby obtaining the core-shell-structure Au@AuPt
alloy nanoparticles, wherein the
reducer A is
ascorbic acid, and the reducer B is a hydrazine
hydrate water solution; and adding
ethanol or
methanol into the
reaction system, carrying out centrifugal
settling, taking the precipitate, and washing the precipitate to obtain the core-shell-structure Au@AuPt
alloy nanoparticle powder. The method has the advantages of simple preparation technique and low
energy consumption.