Wang Jie, Tang Fu, Gao Junheng, Yao Chuang, Zhang Sheng, Li Lidong
State Key Laboratory for Advanced Metals and Materials, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, P. R. China.
Key Laboratory of Extraordinary Bond Engineering and Advance Materials Technology (EBEAM) of Chongqing, Yangtze Normal University, Chongqing 408100, P. R. China.
Nanoscale. 2022 Oct 21;14(40):15091-15100. doi: 10.1039/d2nr04291f.
Cuprous oxide (CuO) mesocrystals, which are composed of numerous nanocrystals with a common crystallographic orientation, are supposed to possess superior photocatalytic abilities than the normal constructions, but very few of them have been reported to date. In this work, plate-like CuO mesocrystals were successfully fabricated a facile one-pot wet chemical strategy. Unlike the commonly used polymers or small molecules, chloride ions (Cl) were employed as structure-directing agents and played the main role in the CuO mesocrystal formation. The formation mechanism was interpreted as follows: the presence of Cl inhibited the formation of CuO and Cu by forming the intermediate product CuCl, which was further hydrolyzed to CuO nanocrystals. Cl tended to adsorb on the (111) facets of the formed CuO nanocrystals and stabilize them. Then the CuO nanocrystals were aligned side by side through the unabsorbed side faces, leading to mutual nanocrystals orientation and crystallographic lock-in, facilitating the formation of plate-like CuO mesocrystals. The polymer, polyacrylamide (PAM), also promoted the mesocrystals formation by serving as a stabilizer and fixed the crystallographic orientation of the CuO nanocrystals during their orderly stacking process. The plate-like CuO mesocrystals showed a long decay time and pronounced performance toward the visible-light-driven photocatalytic reduction of N into NH. This research may stimulate in-depth investigations into the exploration of new synthetic methods for the design and construction of novel mesocrystals.
氧化亚铜（CuO）介晶由许多具有共同晶体取向的纳米晶体组成，被认为比普通结构具有更优异的光催化能力，但迄今为止报道的却很少。在这项工作中，通过一种简便的一锅湿化学策略成功制备了片状CuO介晶。与常用的聚合物或小分子不同，氯离子（Cl）被用作结构导向剂，并在CuO介晶的形成中起主要作用。其形成机理如下：Cl的存在通过形成中间产物CuCl抑制了CuO和Cu的形成，CuCl进一步水解为CuO纳米晶体。Cl倾向于吸附在形成的CuO纳米晶体的（111）晶面上并使其稳定。然后CuO纳米晶体通过未被吸附的侧面并排排列，导致相互的纳米晶体取向和晶体锁定，促进了片状CuO介晶的形成。聚合物聚丙烯酰胺（PAM）也通过作为稳定剂促进了介晶的形成，并在CuO纳米晶体有序堆叠过程中固定了它们的晶体取向。片状CuO介晶表现出较长的衰减时间，并且在可见光驱动的将N还原为NH的光催化反应中表现出显著的性能。这项研究可能会激发对新型介晶设计和构建的新合成方法探索的深入研究。
