近日，中南大学王海鹰团队报道了通过层间阴离子竞争解锁废水中硝酸盐提取的选择性电化学调节。这一研究成果于2025年12月10日发表在《德国应用化学》杂志上。

电化学分离技术为回收工业废水中有价值的氮素提供了有效途径，但其分离效率常受多种离子竞争性静电相互作用的影响。通过设计竞争性化学反应来促进硝酸根的特异性电化学结合，该技术为复杂溶液体系中的高效阴离子分离开辟了新路径。

研究组设计了一种新型的[Bi₂O₂]²⁺层状法拉第电极，其具备可供硝酸根迁移的二维通道及多位点，能通过静电作用与配位力的协同增强硝酸根相互作用。此外，通过策略性引入外源阴离子，在Bi³⁺位点诱导产生的反位阳离子缺陷可强化后续硝酸根插层的配位作用，从而实现182.47 mg g^-1的硝酸根去除容量。同时，高电荷密度的碳酸根能增强其对其他竞争性阴离子的排斥作用，使该电极在多离子溶液中对硝酸根的去除率高达90.78%。

更重要的是，外源性碳酸根插层逆转了硝酸根与硫酸根在层间的结合能顺序：硝酸根取代碳酸根的能量变化（−13.12 eV）在热力学上比硫酸根取代（−12.16 eV）更为有利，从而实现了硝酸根的自发捕获。该工作为设计硝酸根选择性电极提供了新思路，并深化了对阴离子-界面相互作用的理解。

附：英文原文

Title: Unlocking Selective Electrochemical Regulation via Interlayer Anion Competition for Nitrate Extraction from Wastewater

Author: Baixue Ouyang, Rui Huang, Peng Chen, Tingzheng Zhang, Dun Wei, Haoran Dong, Yuewen Qing, Yingjie He, Wenchao Zhang, Haiying Wang, Liyuan Chai

Issue&Volume: 2025-12-10

Abstract: Electrochemical separation technology offers an effective approach to recycle valuable nitrogen from industrial wastewater, but its separation efficiency is reduced by competitive electrostatic interactions from multiple ions. By engineering a competitive chemical reaction to facilitate site-specific electrochemical binding of NO3, this approach offers a promising route for high-efficiency anion separation in complex solutions. Herein, a novel [Bi2O2]2+ layered Faraday electrode was designed with two-dimensional channels for NO3 migration and multiple sites that boost its interaction through combined electrostatic and coordination forces. In addition, by strategically introducing exogenous anions, the induced antisite cation defects at Bi3+ sites enhance the coordination of subsequent NO3 insertion, achieving a NO3 removal capacity of 182.47 mg g1. Meanwhile, the highly charged CO32 enhances its repulsion against other competitive anions, leading to an impressive removal ratio of 90.78% for NO3 in multi-ion solutions. More importantly, exogenous CO32 intercalation reverses the interlayer binding energy hierarchy between NO3 and SO42, converting the substitution by NO3 (13.12 eV) more thermodynamically favorable than that by SO42 (12.16 eV), enabling spontaneous NO3 uptake. Our work provides new insights for designing NO3-selective electrodes, enhancing understanding of anion-interface interactions.

DOI: 10.1002/anie.202522623

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202522623