Synthesis of size-controlled PtCu@Ru nanorattles via Pt seed-assisted formation of size-controlled removable Cu template

A facile synthetic strategy has been developed for size-controlled PtCu@Ru nanorattles via co-decomposition of Ru and Cu precursors in the presence of Pt nanoparticles. The presence of Pt nanoparticles induces a fast decomposition of Cu precursors, leading to the growth of the Cu phase on the Pt seeds. The Pt nanoparticle surface is partially alloyed with the Cu phase to form a PtCu alloy phase. Subsequent decomposition of Ru precursors leads to the formation of the Ru shell. The Cu layer between the core and shell of the intermediate PtCu@Cu@Ru nanoparticle, generated as a kinetic product, is then in situ removed by a CTAB (cetyltrimethylammonium bromide)-induced destabilization process to yield a novel nanorattle structure with a Pt-based core and a porous Ru shell. The diameter of the Ru shell could be conveniently controlled by varying the ratio of employed Cu and Ru precursors.