日本京都大学Toshiharu Teranishi团队报道了离子纳米晶体在阳离子交换反应中晶体结构转变的决定因素。相关研究成果于2021年7月16日发表在《科学》。

离子型纳米晶在阳离子交换反应过程中的晶系变化是不寻常的，有待系统研究。

在该研究中，化学合成和计算模拟表明，六方棱柱状氧化锆（Cu1.8S）纳米晶的高度和扭曲的六方密排硫化物阴离子（S2）亚晶格决定了，阳离子交换产物的最终晶相为Co²⁺[纤锌矿-硫化钴（CoS）和六方密排S2-和/或钴镍黄铁矿（Co9S8），立方密排S^2–]。在温和的反应条件下，暴露平面的热力学不稳定性驱动阴离子骨架的重建。

其他引入的阳离子（Mn²⁺、Zn²⁺、Ni²⁺）通过体积、热力学稳定性和配位环境等多种手段调节阳离子交换反应过程中的晶体结构转变。

附：英文原文

Title: Determinants of crystal structure transformation of ionic nanocrystals in cation exchange reactions

Author: Zhanzhao Li, Masaki Saruyama, Toru Asaka, Yasutomi Tatetsu, Toshiharu Teranishi

Issue&Volume: 2021/07/16

Abstract: Changes in the crystal system of an ionic nanocrystal during a cation exchange reaction are unusual yet remain to be systematically investigated. In this study, chemical synthesis and computational modeling demonstrated that the height of hexagonal-prism roxbyite (Cu1.8S) nanocrystals with a distorted hexagonal close-packed sulfide anion (S2) sublattice determines the final crystal phase of the cation-exchanged products with Co2+ [wurtzite cobalt sulfide (CoS) with hexagonal close-packed S2– and/or cobalt pentlandite (Co9S8) with cubic close-packed S2–]. Thermodynamic instability of exposed planes drives reconstruction of anion frameworks under mild reaction conditions. Other incoming cations (Mn2+, Zn2+, and Ni2+) modulate crystal structure transformation during cation exchange reactions by various means, such as volume, thermodynamic stability, and coordination environment.

DOI: 10.1126/science.abh2741

Source: https://science.sciencemag.org/content/373/6552/332