State Key Laboratory of Power Transmission Equipment & System Safety and New Technology, Chongqing Key Laboratory of Soft Condensed Matter Physics and Smart Materials, College of Physics, Chongqing University, Chongqing, 400044, P.R. China.
State Key Laboratory of Power Transmission Equipment & System Safety and New Technology, Chongqing Key Laboratory of Soft Condensed Matter Physics and Smart Materials, College of Physics, Chongqing University, Chongqing, 400044, P.R. China.
Chemosphere. 2022 Dec;308(Pt 3):136573. doi: 10.1016/j.chemosphere.2022.136573. Epub 2022 Sep 22.
Chromium (VI) removal is crucial to the safety of water resources, but there is still a lack of effective and fast dislodge methods, especially the on-site rapid remediation and emergency removal technology. Herein, the monolayer (ML) TiCT nanosheets (NSs) were prepared to remove Cr (VI) from water. The solution sample of the two-dimensional (2D) TiCT NSs demonstrate ultrafast adsorption kinetics (the concentration decreasing from 300 to 3 mg L in 10 min) and impressively high capacity (1483 mg g), which is several times higher than that of the most reported Cr (VI) adsorption by TiCT. The analysis of the adsorption kinetics and isotherm models indicates that the adsorption reaction is endothermic, with physical and chemical adsorption coexisting (mainly monolayer chemical adsorption). The joint study of the experimental analysis and theoretical calculation based on the density functional theory (DFT) demonstrates that the extraordinary removal performance of Cr (VI) is due to the synergetic effect of reduction reaction removal and electrostatic adsorption. It is found that the Cr (VI) is mainly reduced by the OH- terminals on TiC, and the detoxified Cr (III) is anchored on the surface of TiCT through complexation reaction with O terminal. The advantages of ultrafast adsorption kinetics and extra-high adsorption capacity of the single-layered TiCT for Cr (VI) removal make it a remarkable candidate for rapid and urgent removal of Cr (VI) wastewater.
去除六价铬对于水资源的安全至关重要，但目前仍缺乏有效、快速的洗脱方法，尤其是现场快速修复和应急去除技术。在此，我们制备了单层（ML）TiCT 纳米片（NSs）以去除水中的 Cr（VI）。二维（2D）TiCT NSs 的溶液样品表现出超快的吸附动力学（在 10 分钟内将浓度从 300 降至 3mg/L）和令人印象深刻的高容量（1483mg/g），是大多数报道的 TiCT 吸附 Cr（VI）容量的数倍。吸附动力学和等温线模型的分析表明，吸附反应是吸热的，存在物理和化学吸附共存（主要是单层化学吸附）。基于密度泛函理论（DFT）的实验分析和理论计算的联合研究表明，Cr（VI）的非凡去除性能归因于还原反应去除和静电吸附的协同效应。研究发现，Cr（VI）主要是由 TiC 上的 OH-端还原的，而解毒后的 Cr（III）通过与 O 端的络合反应锚定在 TiCT 的表面上。TiCT 单层对 Cr（VI）的超快吸附动力学和超高吸附容量的优势使其成为快速、紧急去除 Cr（VI）废水的显著候选材料。
