Novel, hierarchical, flower-like Ag/Cu₂O and Au/Cu₂O nanostructures were successfully fabricated and applied as efficient electrocatalysts for the electrochemical reduction of CO₂. Cu₂O nanospheres with a uniform size of ∼180 nm were initially synthesized. Thereafter, Cu₂O was used as a sacrificial template to prepare a series of Ag/Cu2O composites through galvanic replacement. By varying the Ag/Cu atomic ratio, Ag_0.125/Cu₂O, having a hierarchical, flower-like nanostructure with intersecting Ag nanoflakes encompassing an inner Cu₂O sphere, was prepared. The as-prepared Ag_x/Cu₂O samples presented higher Faradaic efficiencies (FE) for CO and relatively suppressed H₂ evolution than the parent Cu₂O nanospheres due to the combination of Ag with Cu₂O in the former. Notably, the highest CO evolution rate was achieved with Ag_0.125/Cu₂O due to the larger electroactive surface area furnished by the hierarchical structure. The same hierarchical flower-like structure was also obtained for the Au_0.6/Cu₂O composite, where the FE_CO (10%) was even higher than that of Ag_0.125/Cu₂O. Importantly, the results reveal that Ag_0.125/Cu₂O and Au_0.6/Cu₂O both exhibit remarkably improved stability relative to Cu₂O. This study presents a facile method of developing hierarchical metal-oxide composites as efficient and stable electrocatalysts for the electrochemical reduction of CO₂.

成功地制备了新颖的，分层的，花状的Ag / Cu ₂ O和Au / Cu ₂ O纳米结构，并将其用作有效的电催化剂，用于电化学还原CO ₂。最初合成了均匀大小约为180 nm的Cu ₂ O纳米球。此后，将Cu ₂ O用作牺牲模板，以通过电置换制备一系列Ag / Cu2O复合材料。通过改变银/铜原子比，银_0.125 / Cu的₂ O，具有层级，花状具有交叉的Ag纳米薄片包围的内部的Cu纳米结构₂ ö球，制备。制备的Ag _x / Cu ₂由于前者中的Ag和Cu ₂ O的结合，O样品表现出比母体Cu ₂ O纳米球更高的CO法拉第效率（FE）和相对抑制的H ₂析出。值得注意的是，由于分层结构提供了更大的电活性表面积，因此使用Ag _0.125 / Cu ₂ O可获得最高的CO释放速率。相同的分层花状结构还为获得的Au _0.6 / Cu的₂ O混合，其中FE _CO（10％）甚至高于银_0.125 /铜₂ O.重要的是，结果表明，银_0.125 /铜₂O和金_0.6 / Cu的₂ ö二者显示出显着的相对改善的稳定性成Cu ₂ O.本研究提出显影分层金属氧化物复合物作为用于电化学还原CO的有效和稳定的电催化剂的方法简便₂。