College of Environmental Science and Engineering, Beijing Key Lab for Source Control Technology of Water Pollution , Beijing Forestry University , Beijing 100083 , China.
Xiong'an Institute of Eco-Environment , Hebei University , Baoding 071002 , China.
Environ Sci Technol. 2019 Aug 6;53(15):9073-9080. doi: 10.1021/acs.est.9b01939. Epub 2019 Jul 9.
Lanthanum (La)-based materials have been recognized as promising adsorbents for aqueous phosphate removal. The incorporation of base metals into La (oxy)hydroxides represents an effective strategy to improve adsorption performance. Understanding how base metals affect phosphate adsorption is challenging but essential for the development of effective materials for phosphorus control. Herein, we demonstrated a high-performance LaFe (oxy)hydroxide and studied its mechanisms on phosphate adsorption. The P K edge X-ray absorption near edge structure (XANES) analysis showed that PO was preferentially bonded with La, and the lattice oxygen in LaFe (oxy)hydroxide was demonstrated to be the active site. The O K edge XANES suggested that Fe optimized the electron structure of La, and Fe/La metal orbital hybridization resulted in the shift of oxygen p character to unoccupied states, facilitating phosphate adsorption. Furthermore, surface analysis showed that the pore size and volume were increased due to the introduction of Fe, which enabled efficient utilization of the active sites and fast adsorption kinetics. The dual effects of Fe in LaFe (oxy)hydroxide greatly enhance the effectiveness of La and represent a new strategy for the development of future phosphorus-control materials.
基于镧的材料已被认为是去除水溶液中磷酸盐的有前途的吸附剂。将基础金属掺入 La（氧）氢氧化物中是提高吸附性能的有效策略。了解基础金属如何影响磷酸盐吸附对于开发有效的磷控制材料是具有挑战性但至关重要的。在此，我们展示了一种高性能的 LaFe（氧）氢氧化物，并研究了其在磷酸盐吸附中的机制。P K 边 X 射线吸收近边结构（XANES）分析表明，PO 优先与 La 键合，并且 LaFe（氧）氢氧化物中的晶格氧被证明是活性位。O K 边 XANES 表明，Fe 优化了 La 的电子结构，Fe/La 金属轨道杂化导致氧 p 特征向未占据态转移，从而促进了磷酸盐的吸附。此外，表面分析表明，由于引入了 Fe，孔径和孔体积增加，从而能够有效利用活性位并实现快速吸附动力学。Fe 在 LaFe（氧）氢氧化物中的双重作用极大地增强了 La 的有效性，代表了未来磷控制材料开发的一种新策略。
