It has been a major challenge to develop stable and cost-effective porous materials that efficiently recover heavy rare earth elements (HREEs) due to ever-increasing demand, low availability and high cost of HREEs. This study presents two novel benzylphosphate-based covalent porous organic polymers (BPOP-1 and BPOP-2) that were prepared by facile one-pot Friedel-Crafts reactions. Various analytical techniques are used to investigate the successful syntheses of BPOP materials and establish their material properties, which include an unusual crystalline nature, large surface area, hierarchical pore structure, and superior chemical stabilities. The BPOPs effectively adsorb, and thus remove HREEs from aqueous media. In particular, BPOP-1 had higher phosphate content and exhibits superior adsorption capacities (Eu³⁺: 289.5; Gd³⁺: 292.7; Tb³⁺: 294.4; Dy³⁺: 301.9 mg/g) than BPOP-2, while BPOP-2 had higher mesoporosity and correspondingly supports faster adsorption kinetics. Remarkably, both BPOP materials exhibit some of the highest HREE adsorption capacities reported to date, the selective capture of Dy³⁺ ions, and excellent cyclic adsorption/desorption properties. We provide a potential adsorption mechanism for Dy³⁺ capture by the BPOP adsorbent. These demonstrate that introducing phosphate functionality into a robust porous polymer backbone with high surface area is a promising strategy for selective HREEs capture from wastewater.

由于重稀土元素的需求不断增长，可用性低且成本高，开发稳定且具有成本效益的多孔材料以有效回收重稀土元素（HREE）一直是一项重大挑战。本研究介绍了两种新型的基于磷酸苄酯的共价多孔有机聚合物（BPOP-1 和 BPOP-2），它们是通过简单的一锅法傅克反应制备的。各种分析技术用于研究 BPOP 材料的成功合成并确定其材料特性，包括不寻常的结晶性质、大表面积、分级孔隙结构和卓越的化学稳定性。BPOPs 有效地吸附，从而从水介质中去除 HREEs。特别是，BPOP-1 具有较高的磷酸盐含量并表现出优异的吸附能力（Eu ³⁺: 289.5; Gd ³⁺：292.7；Tb ³⁺：294.4；Dy ³⁺ : 301.9 mg/g) 比 BPOP-2 高，而 BPOP-2 具有更高的中孔率并相应地支持更快的吸附动力学。值得注意的是，这两种 BPOP 材料都表现出迄今为止报道的一些最高的 HREE 吸附容量、对 Dy ³⁺离子的选择性捕获以及出色的循环吸附/解吸性能。我们为BPOP 吸附剂捕获Dy ³⁺提供了一种潜在的吸附机制。这些表明，将磷酸盐官能团引入具有高表面积的坚固多孔聚合物骨架中是一种从废水中选择性捕获高稀土元素的有前景的策略。