Natural and synthetic clays have been used as adsorbents for removal of heavy metals and dyes from aqueous solution for many decades. In the last decade, exfoliating the natural clays to low dimensional nanosheets or nanotubes for preparation of multifunctional clay-based adsorbents has attracted considerable attention. In this review, we have summarized the removal of heavy metals and dyes by clay-based adsorbents, from natural clays to 1D clay nanotubes and 2D clay nanosheets. Firstly, the structural and adsorption performance of various natural clays (montmorillonite/bentonite/smectite, kaolinite, illite, sepiolite, palygorskite/attapulgite, halloysite) are presented. Then the adsorption of dyes and heavy metals onto modified clays including thermally treated clays, acid-washed clays, inorganic pillared clays and organic modified clays are discussed. Next, we have introduced the novel nano-clay based adsorbents with low dimensional morphologies (2D nanosheets, 1D nanotubes, 1D nanorods and clay-supported nanoparticles). The clay adsorbents with exfoliated nanosheets or nanotubes show dramatically improved performance because of the fully exposed reactive sites and very high specific surface area. More importantly, the nanosheets and nanotubes can be readily composited with coupling agents or functional polymers to prepare multifunctional adsorbents. In addition, the adsorption behaviors of clay-based adsorbents along with factors affecting adsorption, adsorption mechanisms and regeneration of adsorbents have been discussed. Inspired by the natural and modified clays, future suggestions in designing novel adsorbents for various applications have also been suggested.

数十年来，天然和合成粘土一直用作吸附剂，用于从水溶液中去除重金属和染料。在过去的十年中，将天然粘土剥离到低维纳米片或纳米管上以制备多功能的基于粘土的吸附剂引起了相当大的关注。在这篇综述中，我们总结了通过粘土基吸附剂去除重金属和染料的过程，从天然粘土到一维粘土纳米管和二维粘土纳米片。首先，介绍了各种天然粘土（蒙脱石/膨润土/蒙脱石，高岭石，伊利石，海泡石，坡缕石/凹凸棒石，埃洛石）的结构和吸附性能。然后将染料和重金属吸附到改性粘土上，包括热处理粘土，酸洗粘土，讨论了无机柱状粘土和有机改性粘土。接下来，我们介绍了具有低维形貌的新型纳米粘土基吸附剂（2D纳米片，1D纳米管，1D纳米棒和粘土负载的纳米颗粒）。具有剥落的纳米片或纳米管的粘土吸附剂由于完全暴露的反应位和非常高的比表面积而显示出显着改善的性能。更重要的是，纳米片和纳米管可以容易地与偶联剂或功能性聚合物复合以制备多功能吸附剂。此外，还讨论了粘土基吸附剂的吸附行为以及影响吸附剂，吸附机理和吸附剂再生的因素。受到天然和改性粘土的启发，