Five different copper-oxide nanocrystals were prepared by colloidal synthesis to form either cubic, octahedral, rhombic dodecahedral, truncated cubic, or fluffy sphere structures. These Cu-oxide nanocrystals were characterised using scanning electron microscopy, X-ray photoelectron spectroscopy, and UV-vis. The SEM images show that the Cu₂O nanocrystals are relatively uniform and all the crystals have a particle mean diameter below 1000 nm. The smallest particle mean diameter is 411 nm for the rhombic dodecahedral crystals, while the octahedral crystal displays the largest particle mean diameter of 864 nm. The XPS results indicate that the copper is primarily Cu^I in Cu₂O, but some as Cu^II are also present. The apparent optical band gap energies could be determined from the optical properties of the five Cu-oxide nanocrystals, using the classical Tauc equation. The apparent optical band gap energies ranged between 2.04 and 2.14 eV. The Ullmann C-O coupling reaction was used to investigate the catalytic performance of the Cu-oxide nanocrystals. The fluffy sphere gave the highest % conversion, while the rhombic dodecahedral showed the lowest conversion.

中文翻译：

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Cu2O纳米晶体的形态学依赖的Ullmann CO芳构化

通过胶体合成制备了五种不同的氧化铜纳米晶体，以形成立方，八面体，菱形十二面体，截头立方或蓬松球形结构。这些铜氧化物纳米晶体使用扫描电子显微镜，X射线光电子能谱和UV-vis进行了表征。SEM图像表明，Cu ₂ O纳米晶体相对均匀，并且所有晶体的颗粒平均直径低于1000nm。菱形十二面体晶体的最小颗粒平均直径为411 nm，而八面体晶体显示的最大颗粒平均直径为864 nm。的XPS结果表明，铜是主要的Cu^我在Cu中₂ O，但一些以Cu ^II也存在。可以使用经典的Tauc方程从五个Cu-氧化物纳米晶体的光学性质中确定表观光学带隙能量。表观光学带隙能量介于2.04和2.14 eV之间。乌尔曼CO偶联反应用于研究铜氧化物纳米晶体的催化性能。蓬松球体的转化率最高，而菱形十二面体的转化率最低。