The applications and modification of MXene-based absorbents: a review

Water treatment demands have intensified increased due to aggravated environmental pollution. Finding materials to remove toxic contaminants, which include heavy metal ions, organic dyes and radionuclides, have become highly urgent. Adsorption, as one of the widely used water purification technology, has attracted much attention because of its low cost and high efficiency. Traditional adsorbent's applications are limited by their poor selectivity, high recycling cost, and small specific surface area. MXene, an emerging two-dimensional layered material, has attracted much attention owing to its excellent hydrophilicity and adjustable surface properties. Particularly, in the domain of adsorption. A large number of MXene-based adsorbents have shown great promising in numerous researches. Based on this, in order to understand the adsorptive behavior of MXene-based materials, a detailed and comprehensive review is necessary. The purification progress via MXene-based adsorbents is easy to be affected by not only the operating condition of application but also the structure of materials, such as interlayer space and surface group composition. Therefore, this review summarizes recent advances in water treatment via MXene-based adsorbents. The synthesis of MXene used in adsorption is presented. The effect of the structure of MXene on the adsorption of various contaminants by comparing the previous data of the kinetics, isotherms and uptake capacity is discussed. Finally, this article also covers those strategies that can elevate adsorption capacity by changing the structure of MXene.