Li Lingwei, You Hongjun, Zhao Lijun, Zhang Ruiyuan, Amin Muhammad Usman, Fang Jixiang
Key Laboratory for Physical Electronics and Devices of the Ministry of Education, School of Electronic Science and Engineering, Faculty of Electronic and Information Engineering, Xi'an Jiaotong University, Xi'an, Shannxi 710049, P. R. China.
School of Physics, Xi'an Jiaotong University, Xi'an, Shannxi 710049, P. R. China.
J Phys Chem Lett. 2021 Jun 10;12(22):5271-5278. doi: 10.1021/acs.jpclett.1c00669. Epub 2021 Jun 1.
The ability to engineer the surface ligands or adsorbed molecules on colloid nanocrystals (NCs) is important for various applications, as the physical and chemical properties are strongly affected by the surface chemistry. Here, we develop a facile and generalized ionic compound-mediated ligand-exchange strategy based on density functional theory calculations, in which the ionic compounds possess switchable bonding energy when they transfer between the ionized state and the non-ionized state, hence catalyzing the ligand-exchange process. By using an organic acid as the intermediate ligand, ligands such as oleylamine, butylamine, polyvinylpyrrolidone, and poly(vinyl alcohol) can be freely exchanged on the surface of Au NCs. Benefiting from this unique ligand-exchange strategy, the ligands with strong bonding energy can be replaced by weak ones, which is hard to realize in traditional ligand-exchange processes. The ionic compound-mediated ligand exchange is further utilized to improve the catalytic properties of Au NCs, facilitate the loading of nanoparticles on substrates, and tailor the growth of colloid NCs. These results indicate that the mechanism of switchable bonding energy can be significantly expanded to manipulate the surface property and functionalization of NCs that have applications in a wide range of chemical and biomedical fields.
在胶体纳米晶体（NCs）上设计表面配体或吸附分子的能力对于各种应用而言至关重要，因为其物理和化学性质会受到表面化学的强烈影响。在此，我们基于密度泛函理论计算开发了一种简便且通用的离子化合物介导的配体交换策略，其中离子化合物在从离子化状态转变为非离子化状态时具有可切换的键能，从而催化配体交换过程。通过使用有机酸作为中间配体，油胺、丁胺、聚乙烯吡咯烷酮和聚乙烯醇等配体能够在金纳米晶体表面自由交换。受益于这种独特的配体交换策略，具有强键能的配体能够被弱键能的配体所取代，这在传统配体交换过程中难以实现。离子化合物介导的配体交换进一步被用于改善金纳米晶体的催化性能、促进纳米颗粒在基底上的负载以及调控胶体纳米晶体的生长。这些结果表明，可切换键能的机制能够显著扩展以操控纳米晶体的表面性质和功能化，这些纳米晶体在广泛的化学和生物医学领域都有应用。
