Facile fabrication of hollow Pt/Ag nanocomposites having enhanced catalytic properties

摘要

Hollow Pt/Ag composite nanospheres, which show highly enhanced catalytic properties, have been prepared through a galvanic replacement reaction of silver nanopartides dispersed in Pt~(n+)-added water. Pt~(n+), prepared in advance by the partial reduction of Pt~(4+) with weak reducing agents, is readily reduced galvanically to form porous Pt shells, and concomitantly produced Ag~+ diffuses out to produce hollow Pt/Ag nanocomposites finally. The residual silver has been further eliminated from the composites with 0.5 M HN03(aq) to produce hollow Pt nanospheres. Hollow Pt/Ag composite nanostructures have been found to catalyze the degradation of rhodamine B efficiently in the presence of KBH4, although their catalytic performances depend highly on the metals, sizes, and shapes of the nanostructures.