The crystal phase-based heterostructures of noble metal nanomaterials are of great research interest for various applications, such as plasmonics and catalysis. However, the synthesis of unusual crystal phases of noble metals still remains a great challenge, making the construction of heterophase noble metal nanostructures difficult. Here, we report a one-pot wet-chemical synthesis of well-defined heterophase fcc-2H-fcc gold nanorods (fcc: face-centred cubic; 2H: hexagonal close-packed with stacking sequence of “AB”) at mild conditions. Single particle-level experiments and theoretical investigations reveal that the heterophase gold nanorods demonstrate a distinct optical property compared to that of the conventional fcc gold nanorods. Moreover, the heterophase gold nanorods possess superior electrocatalytic activity for the carbon dioxide reduction reaction over their fcc counterparts under ambient conditions. First-principles calculations suggest that the boosted catalytic performance stems from the energetically favourable adsorption of reaction intermediates, endowed by the unique heterophase characteristic of gold nanorods.

贵金属纳米材料的基于晶相的异质结构在等离子体和催化等各种应用中具有很大的研究兴趣。然而，贵金属异常晶相的合成仍然是一个巨大的挑战，使得异相贵金属纳米结构的构建变得困难。在这里，我们报告了在温和条件下一锅湿化学合成明确的异相 fcc-2H-fcc 金纳米棒（fcc：面心立方；2H：六方密堆积，堆叠顺序为“AB”）。单粒子级实验和理论研究表明，与传统的面心立方金纳米棒相比，异相金纳米棒表现出独特的光学特性。此外，在环境条件下，多相金纳米棒对二氧化碳还原反应具有比 fcc 对应物更优异的电催化活性。第一性原理计算表明，催化性能的提高源于金纳米棒独特的异相特性赋予反应中间体的有利吸附。