A DFT-designed neodymium ion-imprinted membrane with fouling resistance and high flux

• Published in: Journal of membrane science 2024-08, Vol.708, p.123047, Article 123047
• Main Authors: Li, Yue, Tian, Jiewen, Li, Yao, He, Hongxing, Deng, Xiujun, Ju, Haidong, Tao, Rao, Chen, Wen-Tong, Hu, Guangzhi
• Format: Article
• Language: English
• Subjects: DFT calculation; Ion-imprinted membrane; Neodymium; Selectivity; XDLVO theory
• ISSN: 0376-7388; 1873-3123
• DOI: 10.1016/j.memsci.2024.123047

The rare earth metal neodymium (Nd) is widely used in advanced industries such as hybrid cars and aerospace. Therefore, recovering neodymium from wastewater presents valuable opportunities for secondary recycling. The recovery of Nd3+ from wastewater using ion imprinting technology (IIT) for efficient selective separation holds significant importance. In this study, hydrophilic Nd(III) ion-imprinted membranes, termed Nd(III)–P/P/TIIM, were synthesized using the IIT technique. Nd(III)–P/P/TIIM exhibited efficient and selective separation capabilities for Nd3+ with a remarkable retention rate of 95.68 % and a high water flux reaching up to 636.94 L·m−2·h−1. Additionally, its relative selectivity coefficients for interfering ions (KLa, KEu, KCu) were 3.9, 29.5, and 37.9, respectively. Various analyses, including DFT calculations, HOMO and LUMO calculations, MEP images, and XPS spectroscopy, confirm that the mechanism of selective retention of Nd3+ by Nd(III)–P/P/TIIM in solution is due to Coulombic adsorption between the –COO− anion and Nd3+ as well as an imprint memory effect. Even after undergoing three water-BSA cycles, the membrane maintained a water flux of 357.96 L·m−2·h−1. The antifouling principle of Nd(III)–P/P/TIIM was investigated by XDLVO theory, attributed to the increase of electron donor tension (γ−) and Lewis acid-base interactions (ΔGAB) at the membrane surface. This work provides an insightful guidance for engineering high-performance membranes and has the potential to provide an alternative method for recycling neodymium. [Display omitted] •A composite membrane with high neodymium selectivity is prepared.•The membrane exhibited high water flux of 636.94 L·m−2·h−1.•DFT, HOMO and LUMO calculations elucidate the mechanism of separating Nd3+.•The antifouling mechanism is deduced through XDLVO theory.