We report a facile solution-phase sonochemical route for the glucose-template mediated synthesis of Cu₂O nanocrystals with well-defined sizes and shapes. This approach offers a superficial and cost-effective route for the synthesis of Cu₂O nanocrystals. The formation of different nanostructures (i.e., stars, cubes, and octahedra) was tuned by varying the reaction conditions as well as the concentration of template. The morphology-controlled Cu₂O nanocrystals show high activity for the external base-free Ullmann homocoupling reactions of aryl halides. 61.6% conversion of chlorobenzene was achieved over octagonal Cu₂O nanocrystals with a turn-over-frequency (TOF) as high as 1696 h⁻¹. This result demonstrates that the size and shape-dependent properties of Cu₂O nanocrystals are critical to the activity of aryl halide and highlights the importance of shape engineering in the design and development of an efficient catalyst for the Ullmann reaction.

中文翻译：

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无钯CC偶联反应的亚纳米Cu2O催化剂的合成

我们报告了葡萄糖-模板介导的具有明确定义的尺寸和形状的Cu ₂ O纳米晶体的葡萄糖溶液介导的合成的简便溶液相声化学途径。这种方法为合成Cu ₂ O纳米晶体提供了一条表面且经济有效的途径。通过改变反应条件以及模板的浓度，可以调节不同纳米结构（即星，立方体和八面体）的形成。形态控制的Cu ₂ O纳米晶体对芳基卤化物的外部无碱Ullmann均偶联反应显示出高活性。在八角形的Cu ₂ O纳米晶体上，转换频率（TOF）高达1696 h ^-1的氯苯的转化率达到61.6％。。该结果表明，Cu ₂ O纳米晶体的尺寸和形状依赖性对芳基卤化物的活性至关重要，并突出了形状工程在设计和开发用于Ullmann反应的有效催化剂中的重要性。