Novel hollow sub-microspheres with movable Au nanoparticles and excessive Pt nanoparticles in core and silica as shell

A simple route has been designed for the syntheses of a kind of electrocatalyst, i.e., hollow spheres with Au and excessive Pt nanoparticles in core and silica as shell. The Au@carbon spheres synthesized by hydrothermal process can act as the transitional templates, and the carbonaceous matrix can in situ reduce H2PtCl6·H2O solution and load with Pt nanoparticles, and then a slightly modified Stöber process was applied to encapsulate the structures with silica shell. Further calcination at high temperatures removed the carbon matrix to form the hollow spheres with Au and excessive Pt nanoparticles in core and silica as shell. This new kind of structures shows excellent electrocatalytic properties compared with that of similar hollow spheres but only with pure Pt nanoparticles inside, and it might provide an efficient way to improve the electrocatalytic property of a bulk Pt/GC electrode.