Synthesis of Au and Pt Hollow Capsules with Single Holes via Pickering Emulsion Strategy

Au and Pt hollow capsules with single holes were synthesized via a Pickering emulsion strategy. Pickering emulsions provided particles with oil–water interfaces as asymmetric platform for anisotropic structure sculpture. Reactive Cu 2 O particles were utilized not only as emulsifier to prepare Pickering emulsions but also as sacrificed hard template for the consequent asymmetric galvanic reaction at the oil–water interfaces, resulting in the formation of open-mouthed Au and Pt hollow capsules. The opened hollow structure can facilitate the diffusion of reactants to inner side of the shell wall, thus effectively activating the catalytic activity of the inner shell wall of the hollow capsules. The obtained open-mouthed Au hollow capsules show much higher catalytic performance than that of intact Au hollow capsules.