MoS_2纳米片去除水中Cr(Ⅵ)的吸附性能和机理

Adsorption Efficiency and Mechanism of MoS_2 Nano-sheets for Cr(Ⅵ)Removal from Aqueous Solution

采用简单的一步水热法合成了薄片状纳米MoS_2并将其用于吸附去除水中Cr(Ⅵ)。片状MoS_2对Cr(Ⅵ)具有非常好的吸附效果,反应不到160min就达到了吸附平衡,Cr(Ⅵ)的去除率可达97%。Cr(Ⅵ)在MoS_2上的表面吸附是自发吸热的化学吸附过程,反应速率主要由扩散速率控制。其反应动力学符合准二级动力学模型,由Langmuir等温线计算的最大平衡吸附量为36.22mg·g^(-1)。实验结果表明MoS_2纳米片是一种优良的金属离子吸附剂。

MoS2 nano-sheets,fabricated by a facile hydrothermal synthesis,was used for Cr（Ⅵ）removal from contaminate water.The removal efficiency of MoS2 for Cr（Ⅵ）was 97% in no more than 160 min and the maximum adsorption capacity was 36.22 mg·g^-1.The investigation on adsorption kinetics and isotherm showed that the pseudo-second-order kinetic and Langmuir isotherm models could well fit the adsorption experimental process.Adsorption thermodynamics investigation proved that the Cr（Ⅵ）adsorption on the surface of MoS2 was a spontaneous endothermic physic-chemical process,in which the rate of adsorption was controlled by exterior surface diffusion step.It illustrated that MoS2 nano-sheets can be used as excellent adsorbent for heavy metal ions removal from wastewater.