Montero-Muñoz M, Ramos-Ibarra J E, Rodríguez-Páez J E, Marques G E, Teodoro M D, Coaquira J A H
Institute of Physics, University of Brasília, 70910-900 Brasília-DF, Brazil.
Phys Chem Chem Phys. 2020 Apr 14;22(14):7329-7339. doi: 10.1039/c9cp06744b. Epub 2020 Mar 25.
A shape-selective preparation method was used to obtain highly crystalline rod-, needle-, nut-, and doughnut-like ZnO morphologies with distinct particle sizes and surface areas. We study the nucleation and growth mechanism of those structures and the influence of physical-chemical parameters, such as the solvent and the pH of the solution, on the morphology, as well as the structural and optical properties. A clear correlation between the growth rate along the c-axis and surface defects was established. Our results suggest that the needle- and rod-like morphologies are formed due to the crystal growth orientation along the c-axis and the occurrence of crystalline defects, such as oxygen vacancies and interstitial Zn located at the surface, whereas nuts and doughnuts are formed due to growth along all crystalline planes except those related to growth along the c-axis. Based on the experimental results, growth mechanisms for the formation of ZnO structures were proposed. We believe this synthetic route will be of guidance to prepare several materials whose shapes will depend on the desired applications.
采用形状选择制备方法获得了具有不同粒径和表面积的高度结晶的棒状、针状、螺母状和甜甜圈状的氧化锌形态。我们研究了这些结构的成核和生长机制，以及物理化学参数（如溶剂和溶液的pH值）对形态以及结构和光学性质的影响。建立了沿c轴的生长速率与表面缺陷之间的明确关联。我们的结果表明，针状和棒状形态是由于沿c轴的晶体生长取向以及表面存在的晶体缺陷（如氧空位和间隙锌）而形成的，而螺母状和甜甜圈状则是由于沿除与沿c轴生长相关的晶面之外的所有晶面生长而形成的。基于实验结果，提出了氧化锌结构形成的生长机制。我们相信这条合成路线将为制备几种形状取决于所需应用的材料提供指导。
