School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, Singapore 637459, Singapore.
College of Materials Science and Engineering, Zhejiang University of Technology, Hangzhou 310014, China.
Sci Adv. 2019 Dec 13;5(12):eaax5095. doi: 10.1126/sciadv.aax5095. eCollection 2019 Dec.
The ability to construct discrete colloidal clusters (CCs) as complex as molecular clusters is limited due to the lack of available colloidal building blocks and specific directional bonds. Here, we explore a strategy to organize anisotropic Prussian blue analog nanocrystals (NCs) toward CCs with open and highly ordered structures, experimentally realizing colloidal analogs to zeolitic clathrate structures. The directional interactions are derived from either crystallographic or morphological anisotropy of the NCs and achieved by the interplay of epitaxial growth, oriented attachment, and local packing. We attribute these interparticle interactions to enthalpic and entropic valences that imitate hybridized atomic orbitals of octahedron and cube. Benefiting from the ordered multilevel porous structures, the obtained CCs exhibit greatly enhanced catalytic activity for CO photoreduction. Our work offers some fundamental insights into directional bonding among NCs and opens an avenue that promises access to unique CCs with unprecedented structures and applications.
由于缺乏可用的胶体构建块和特定的定向键，构建像分子簇一样复杂的离散胶体簇 (CC) 的能力受到限制。在这里，我们探索了一种将各向异性普鲁士蓝类似物纳米晶体 (NC) 组织成具有开放和高度有序结构的 CC 的策略，实验上实现了沸石笼状结构的胶体类似物。方向性相互作用源于 NC 的晶体学或形态各向异性，并通过外延生长、定向附着和局部堆积的相互作用来实现。我们将这些颗粒间相互作用归因于焓和熵价，它们模拟了八面体和立方体的杂化原子轨道。得益于有序的多层次多孔结构，所得到的 CC 对 CO 光还原表现出极大增强的催化活性。我们的工作为 NC 之间的定向键合提供了一些基本的见解，并开辟了一条途径，有望获得具有前所未有的结构和应用的独特 CC。
