Gendler Danielle, Bi Jiaying, Mekan Deep, Warokomski Ashley, Armstrong Cameron, Hernandez-Pagan Emil A
Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, USA.
Nanoscale. 2023 Feb 9;15(6):2650-2658. doi: 10.1039/d2nr05854e.
Devising synthetic strategies to control crystal structure is of great importance as materials properties are governed by structure. MnS is a great model system as it has three known stable polymorphs. Herein, we show the selective synthesis of colloidal wurtzite- and rock-salt-type MnS under identical reactions conditions changing only the manganese halide precursor. Mixtures of Mn halides or halide surrogate (, NHCl) also enabled polymorph control. Powder X-ray diffraction aliquot studies of the reactions revealed the crystal structure at the onset of nucleation and that of the final product is the same, unlike the Ostwald ripening transformation observed in other systems. The halide-driven selectivity was also observed in the synthesis of manganese selenide nanoparticles. In this system, variation of the Mn halide precursor allowed access to the wurtzite- and rock salt-type polymorphs of MnSe, as well as the pyrite-MnSe phase. Based on this work, the mixing of metal salts might be a simple and effective strategy towards polymorph control and access materials with new crystal structures.
由于材料性能由结构决定，因此设计控制晶体结构的合成策略非常重要。硫化锰是一个很好的模型体系，因为它有三种已知的稳定多晶型物。在此，我们展示了在相同反应条件下，仅改变卤化锰前驱体，选择性合成胶体纤锌矿型和岩盐型硫化锰。卤化锰或卤化物替代物（如氯化铵）的混合物也能实现多晶型控制。对反应进行的粉末X射线衍射等分试样研究表明，成核开始时的晶体结构与最终产物的晶体结构相同，这与在其他体系中观察到的奥斯特瓦尔德熟化转变不同。在硒化锰纳米颗粒的合成中也观察到了卤化物驱动的选择性。在这个体系中，改变卤化锰前驱体可以得到纤锌矿型和岩盐型的硒化锰多晶型物，以及黄铁矿型硒化锰相。基于这项工作，金属盐的混合可能是一种简单有效的多晶型控制策略，能够获得具有新晶体结构的材料。
