The development of rare earth adsorbent with high adsorption capacity and rapid adsorption rate is one of the most important issues for enriching and recovering rare earth ions. In the present work, an inorganic phosphorous acid-modified mesoporous SBA-15 (P-SBA-15) was facilely synthesized by a simple and cost-effective post-grafting approach, and its adsorption behavior towards the rare earth ion Gd(III) was investigated. Benefiting from high specific surface area (669.7 m 2 ·g −1 ), large pore size (9.1 nm), and the presence of abundant phosphorous acid groups (1.4 mmol·g −1 ) on the surface, the P-SBA-15 exhibited an excellent performance in terms of capacity and kinetics on adsorption of Gd(III). Under optimized conditions, the adsorption capacity of P-SBA-15 towards Gd(III) was up to 1.3 mmol·g −1 at 30 °C, which is the second highest value as compared with previously reported Gd(III) adsorbents. Moreover, the adsorption of Gd(III) onto P-SBA-15 was ultrafast, achieving adsorption equilibrium within only 2 min. Test of reusability revealed that this mesoporous adsorbent could be repeatedly used several times without significant loss in binding capacity. This work not only provides a new insight into the fabrication of phosphorous acid-functionalized mesoporous silica, but also demonstrates its prospective application in adsorptive removal and/or recovery of rare earth ions.
Gang Zhang,Wenxia Ma,Yuqin Feng,Ming Yang,Zheng Fang,Yongsheng Yang,Weiyan Yin,Zehao Li
The development of rare earth adsorbents with high adsorption capacity, outstanding selectivity, and excellent reusability is important for the enrichment and recovery of rare earth elements. The adsorption of the rare earth ion Gd(III) by a phosphorylated polyacrylonitrile fiber was investigated. In this work, the adsorbent was synthesized by a simple and cost-effective grafting method using polyacrylonitrile (PAN) fibers as the substrates. The FTIR analysis, SEM, XPS, and TGA indicated the successful synthesis of polyacrylonitrile-phosphite (PAN-Phos) fibers. To evaluate the feasibility of PAN-Phos fibers as the potential adsorbents for Gd(III) removal, a series of adsorption experiments were conducted. The pseudo-second-order kinetic model better illustrated the adsorption of Gd(III) on PAN-Phos fibers, and equilibrium adsorption was achieved within 50 min; the maximum adsorption capacity was 120.9 mg·g–1. The PAN-Phos fibers also exhibited excellent reproducibility after four adsorption cycles. In addition, the results of various analyses indicated that the adsorption mechanism of Gd(III) on PAN-Phos fibers was mainly through the synergistic complexation of secondary amine and phosphoric acid groups. It provided a practicable way for the synthesis and preparation of rare earth adsorbent materials.
危险品化学品经营许可证（带存储）