Salt removal from seawater and brackish water by Capacitive deionization (CDI) is an emerging technology that has a potential to contribute to solving global shortages of freshwater. Upon the application of an external voltage to a pair of nanostructured carbon electrodes, ions are removed by electrosorption in the electrical double layer (EDL) of the capacitor. The physical limitation due to repulsion of co-ions can be reduced using intercalation materials that are less sensitive to ion concentration variations. Herein, we report a hollow-concave high-entropy Prussian blue analogue (HEPBA) enhanced electrodes for superior electrochemical and capacitor performances. The half-cell of hollow-concave HEPBA has a high cycling stability of 1000 cycles at a current density of 1 A g−1. Lower energy consumption for desalination estimated over 90 cycles is due to an enhancement of salt adsorption capacity of HEPBA (∼ 26.2 mg g−1). The observed improvement in the electrochemical property is due to synergistic effects from multi-elemental composition that lead to the high entropy and specific surface area. Hollow-concave HEPBA are structurally stable with negligible changes in the lattice parameters during extensive charging and discharging cycles. This simple method offers an opportunity to modify the structure and morphology of PBAs for real-life applications.

中文翻译：

---

用于盐水电容去离子的高熵普鲁士蓝类似物的微观结构工程


通过电容去离子 （CDI） 从海水和苦咸水中脱盐是一项新兴技术，有可能为解决全球淡水短缺问题做出贡献。在对一对纳米结构碳电极施加外部电压后，离子通过电容器双电层 （EDL） 中的电吸附去除。使用对离子浓度变化不太敏感的插层材料可以减少由于共离子排斥而导致的物理限制。在本文中，我们报道了一种空心凹高熵普鲁士蓝类似物 （HEPBA） 增强电极，具有卓越的电化学和电容器性能。空心凹 HEPBA 的半电池在 1 A g−1 的电流密度下具有 1000 次循环的高循环稳定性。据估计，超过 90 次循环的海水淡化能耗较低是由于 HEPBA 的盐吸附能力增强 （∼ 26.2 mg g-1）。观察到的电化学性能的改善是由于多元素组成的协同效应导致高熵和比表面积。空凹 HEPBA 在广泛的充电和放电循环中结构稳定，晶格参数的变化可以忽略不计。这种简单的方法为修改 PBA 的结构和形态以适应实际应用提供了机会。