Zhang Jiawei, Li Huiqi, Kuang Qin, Xie Zhaoxiong
State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, College of Chemistry and Chemical Engineering , Xiamen University , Xiamen 361005 , China.
Pen-Tung Sah Institute of Micro-Nano Science and Technology , Xiamen University , Xiamen 361005 , China.
Acc Chem Res. 2018 Nov 20;51(11):2880-2887. doi: 10.1021/acs.accounts.8b00344. Epub 2018 Oct 22.
Tailoring the surface structures of nanocrystals is an exciting research area on account of appealing surface-dependent properties in various applications. Although significant progress has been made in recent years, current synthetic approaches are mainly dependent upon trial and error because of the ambiguous roles of various influencing factors in complicated environments. Therefore, a general theory for predicting and guiding the rationally controlled synthesis of micro- and nanocrystallites with specific surface structures is highly desired. Of note, previous research attention was mainly focused on the crystal growth in near equilibrium conditions. However, in supersaturated growth environments (nonequilibrium conditions), the corresponding crystal growth theories are still limited. Recently, the supersaturation-controlled surface structure strategy, which is derived from thermodynamics and the Thomson-Gibbs equation, has opened up a new avenue for the control the surface structures of crystals. This strategy involves manipulating the supersaturation of growth units to control the surface structure of micro- and nanocrystallites, as the surface energy of exposed facets is correlated to the supersaturation of growth blocks. Based on the proposed theory, micro- and nanocrystallites with various surface structures, especially high-energy facets, have been successfully synthesized by our group and other researchers in past years. In order to draw lessons from previous studies, it is imperative to give a timely research account related to the supersaturation strategy and corresponding applications in controlling surface structures of different crystallites. In this Account, we explore the supersaturation-controlled surface structure strategy to construct functional nanomaterials with desired architectures. First, we highlight the role of supersaturation of growth units from theoretical analysis after a short introduction of fundamental principles for crystal growth. Then, some detailed cases concerning evolution of surface structures are presented to highlight the key experimental factors involved in manipulating the supersaturation of growth units during synthetic processes. These factors include solvents, reaction rates, and additives in wet chemical routes as well as overpotential in electrochemical routes. In addition, we briefly discuss the role of supersaturation in growth kinetics with focus on explaining the formation of spherical micro- and nanocrystallites at extremely high supersaturation. Finally, a general summary of the supersaturation-dependent surface structure control and future prospects in this field are provided. It is expected that this Account will deepen the current understanding on fundamental principles behind the control of surface structures of micro- and nanocrystallites, which can help us to construct desirable nanomaterials and promote their practical applications.
鉴于纳米晶体在各种应用中具有吸引人的表面相关特性，定制其表面结构是一个令人兴奋的研究领域。尽管近年来已取得显著进展，但由于复杂环境中各种影响因素的作用尚不明确，目前的合成方法主要依赖反复试验。因此，迫切需要一种用于预测和指导合理控制合成具有特定表面结构的微晶和纳米晶体的通用理论。值得注意的是，以往的研究主要集中在近平衡条件下的晶体生长。然而，在过饱和生长环境（非平衡条件）中，相应的晶体生长理论仍然有限。最近，源自热力学和汤姆森 - 吉布斯方程的过饱和度控制表面结构策略，为控制晶体表面结构开辟了一条新途径。该策略涉及通过操纵生长单元的过饱和度来控制微晶和纳米晶体的表面结构，因为暴露晶面的表面能与生长块的过饱和度相关。基于所提出的理论，近年来我们团队和其他研究人员已成功合成了具有各种表面结构，特别是高能晶面的微晶和纳米晶体。为了从以往研究中吸取经验教训，及时给出与过饱和度策略及其在控制不同晶体表面结构方面的相应应用相关的研究报告是必要的。在本报告中，我们探索过饱和度控制表面结构策略以构建具有所需结构的功能纳米材料。首先，在简要介绍晶体生长基本原理后，我们从理论分析突出生长单元过饱和度的作用。然后，给出一些关于表面结构演变的详细案例，以突出在合成过程中操纵生长单元过饱和度所涉及的关键实验因素。这些因素包括湿化学路线中的溶剂、反应速率和添加剂以及电化学路线中的过电位。此外，我们简要讨论过饱和度在生长动力学中的作用，重点解释在极高过饱和度下球形微晶和纳米晶体的形成。最后，提供了过饱和度依赖表面结构控制的一般总结以及该领域的未来前景。预计本报告将加深目前对控制微晶和纳米晶体表面结构背后基本原理的理解，这有助于我们构建理想的纳米材料并促进其实际应用。
