层状复合氢氧化物的结构调控及其吸附重金属离子的研究进展

层状复合氢氧化物(Layered Double Hydroxides, LDHs)是一种具有特殊层状结构的阴离子黏土,其具有化学组成可调、比表面积大及独特的结构记忆效应等性质,因此在废水处理方面广受关注。调控LDHs自身结构是进一步扩大其应用范围,提高其吸附性能的有效途径。首先介绍了LDHs特殊的层状结构和其自身性质。其次,主要总结了LDHs最常用的五种制备方法,即共沉淀法、离子交换法、尿素水解法、煅烧复原法和溶胶-凝胶法,分别介绍了各种制备方法的原理和特点。然后综述了LDHs的结构调控对其吸附重金属离子性能的影响,并总结了LDHs对重金属离子的吸附机理。最后,指出了目前LDHs在处理含有重金属离子废水研究中面临的挑战,并对该材料未来的研究方向和发展趋势进行了展望。

Progress of structural tuning and adsorption of heavy metal ions by layered double hydroxides

Layered double hydroxides (LDHs) are anionic clay with a special layered structure, which are of great interest for wastewater treatment because of their adjustable chemical composition, large specific surface area and unique structural memory effect. Tuning the structure of LDHs is an effective way to further expand its application and improve its adsorption performance. The special layered structure of LDHs and their own properties are firstly introduced. Secondly, the five most commonly used preparation methods of LDHs, namely co-precipitation, ion exchange, urea hydrolysis, calcination recovery and sol-gel method, are mainly summarized, and the principles and characteristics of each preparation method are introduced respectively. Then the influence of structural tuning of LDHs on their adsorption performance for heavy metal ions are reviewed, and the adsorption mechanism of LDHs on heavy metal ions is summarized. Finally, the challenges faced by the current research on LDHs in the treatment of wastewater containing heavy metal ions are pointed out, and the future research directions and development trends of the materials are prospected.