Abstract：
The growing concern of water pollution is a critical issue stemming from industrialization and urbanization. One of the specific concerns within this broader problem is the toxicity associated with chromium (Cr), especially in its Cr (VI) form. Transition metal carbides/nitrides (MXenes) are attractive materials for the treatment of water due to their unique properties such as layered structure, high surface area, conductivity, flexibility, scalable manufacture, and surface functions. Adsorption and photocatalysis reactions are the two promising methods for the removal of Cr (VI) by using MXenes. Still, most of the previous reviews were limited to the single application area. Hence, this review covers recent developments in MXene-based composites, highlighting their dual role as both adsorbents and photocatalysts in the removal of Cr (VI). MXene-based composites are found to be effective in both adsorption and photodegradation of Cr (VI). Most MXene-based composites have demonstrated exceptional removal efficiency for Cr (VI), achieving impressive adsorption capacities ranging from 100 to 1500 mg g-1 and degradation percentages between 80% and 100% in a relatively short period. The active functional groups present on the surface of MXene have a viable impact on the adsorption and photodegradation performance. The mechanism of Cr (VI) removal is explained, with MXenes playing a key role in electrostatic attraction for adsorption and as co-catalysts in photocatalysis. However, MXene-based composites have limitations such as instability, competition with co-existing ions, and regeneration challenges. Further research is needed to address these limitations. Additionally, MXene-based composites hold promise for addressing water contamination, heavy metal removal, hydrogen production, energy storage, gas sensing, and biomedical applications.
摘要：
对水污染的日益关注是源于工业化和城市化的关键问题。在这个更广泛的问题中的一个具体问题是与铬（Cr）相关的毒性，尤其是其Cr(VI)形式。过渡金属碳化物/氮化物（MXenes）是有吸引力的材料用于水的处理由于其独特的性能，如层状结构，高表面积,电导率，灵活性,可扩展的制造，和表面功能。吸附和光催化反应是使用MXenes去除Cr（VI）的两种有前途的方法。尽管如此，以前的大多数审查仅限于单一应用领域。因此，这篇综述涵盖了MXene基复合材料的最新发展，强调了它们在去除Cr（VI）中作为吸附剂和光催化剂的双重作用。发现MXene基复合材料对Cr（VI）的吸附和光降解均有效。大多数MXene基复合材料对Cr（VI）具有出色的去除效率，在相对较短的时间内实现100至1500mg/g的令人印象深刻的吸附能力和80％至100％的降解百分比。MXene表面上存在的活性官能团对吸附和光降解性能具有可行的影响。解释了Cr(VI)的去除机理,MXenes在静电吸附中起关键作用，并在光催化中用作助催化剂。然而,MXene基复合材料具有不稳定性等局限性，与共存离子的竞争，和再生挑战。需要进一步的研究来解决这些限制。此外,MXene基复合材料有望解决水污染问题，重金属去除，制氢,储能，气体传感,和生物医学应用。
