Highly dispersed layered double oxide hollow spheres with sufficient active sites for adsorption of methyl blue
Highly dispersed layered double oxide hollow spheres with sufficient active sites for adsorption of methyl blue
复制标题
高度分散的层状双氧化物空心球，具有足够的吸附甲基蓝的活性位点
作者：
Zong Yingtong;Li Kaitao;Tian Rui;Lin Yanjun;Lu Chao
染料废水的吸附处理是解决环境危机的有效途径。层状双金属氢氧化物（LDH）及其焙烧产物层状双金属氧化物（LDO）作为吸附剂具有很好的应用前景。然而，LDH或LDO的常规制备通常遭受聚集和封闭的活性位点，阻碍了吸附剂的吸附效率。本文中，通过牺牲碳模板来构建三维中空MgFe-LDO球。中空结构和单分散状态为MgFe-LDO提供了足够的微通道和丰富的吸附活性位。通过LDO的记忆效应，可以有效地吸附阴离子甲基蓝（MB），其吸附容量高达398 mg g−1。等温线模拟表明，MB的单层吸附和非均匀表面的重建LDHs。此外，吸附剂可以通过磁分离和煅烧至少重复使用5次。我们提出的策略有望为构建具有良好控制结构和丰富活性位点的吸附剂处理阴离子污染物提供新的可能性。
The adsorption of dyes in contaminated water is an effective approach to solving the environmental crisis. Layered double hydroxide (LDH) and its calcinated product layered double oxide (LDO) show great potential as adsorbents. However, the conventional preparation of LDH or LDO typically suffers from aggregation and blocked active sites, hampering the adsorption efficiency of the adsorbent. Herein, three-dimensional, hollow MgFe-LDO spheres were constructed through the sacrifice of a carbon template. The hollow structure and the monodisperse state provided MgFe-LDO with sufficient microchannels and abundant active sites for adsorption. Through the memory effect of LDO, the anion methyl blue (MB) can be effectively adsorbed with a high uptake capacity of 398 mg g−1. Isotherm simulations demonstrated the monolayer adsorption of MB and the heterogeneous surfaces of the reconstructed LDHs. Moreover, the adsorbents can be recycled and reutilized at least five times through magnetic separation followed by calcination. Our proposed strategy is expected to provide new possibilities for the construction of adsorbents with well-controlled architecture and abundant active sites to deal with anionic pollutants.