In the controlled synthesis of noble metal nanostructures using wet-chemical methods, normally, metal salts/complexes are used as precursors, and surfactants/ ligands are used to tune/stabilize the morphology of nanostructures. Here, we develop a facile electrochemical method to directly convert Pt wires to Pt concave icosahedra and nanocubes on carbon paper through the linear sweep voltammetry in a classic three-electrode electrochemical cell. The Pt wire, carbon paper and Ag/AgCl (3 mol L⁻¹ KCl) are used as the counter, working and reference electrodes, respectively. Impressively, the formed Pt nanostructures exhibit better electrocatalytic activity towards the hydrogen evolution compared to the commercial Pt/C catalyst. This work provides a simple and effective way for direct conversion of Pt wires into well-defined Pt nanocrystals with clean surface. We believe it can also be used for preparation of other metal nanocrystals, such as Au and Pd, from their bulk materials, which could exhibit various promising applications.

濕化學法可控合成貴金屬納米結構通常需要金屬鹽或金屬配合物作為前體, 並利用表面活性劑和配體來調節和穩定納米結構的形 貌. 本文通過一種簡單的電化學方法(線性掃描伏安法), 在三電極體系中直接把鉑線轉化到碳布表面形成鉑二十面體和納米立方體. 在三 電極體系中, 鉑線、碳布和Ag/AgCl(3 mol L⁻¹ KCl)分別作為對電極、工作電極和參比電極. 與商業Pt/C催化劑相比, 製備的鉑二十面體和 納米立方體展現出優越的電催化活性. 該方法簡單、有效, 可拓展到其他貴金屬納米結構的合成和應用研究. 如通過這種電化學方法直接 將Au、Pd等塊體材料轉化成具有各種潛在應用的Au、Pd等納米結構.