LAUSR

Crystal phase can greatly affect the physicochemical properties and applications of nanomaterials. However, it still remains a great challenge to synthesize nanostructures with the same composition and morphology but different phases in order to explore the phase-dependent properties and applications. Herein, we report the crystal phase-controlled synthesis of PtCu alloy shells on 4H Au nanoribbons (NRBs), referred to as 4H-Au NRBs, to form the 4H-Au@PtCu core-shell NRBs. By tuning the thickness of PtCu, 4H-PtCu and face-centered cubic (fcc) phase PtCu (fcc-PtCu) alloy shells are successfully grown on the 4H-Au NRB cores. This thickness-dependent phase-controlled growth strategy can also be used to grow PtCo alloys with 4H or fcc phase on 4H-Au NRBs. Significantly, when used as electrocatalysts for the ethanol oxidation reaction (EOR) in alkaline media, the 4H-Au@4H-PtCu NRBs show much better EOR performance than the 4H-Au@fcc-PtCu NRBs, and both of them possess superior performance compared to the commercial Pt black. Our study provides a strategy on phase-controlled synthesis of nanomaterials used for crystal phase-dependent applications.