In this study, the organic-inorganic hybrid materials of polyaniline/Mg-Al layered double oxides (PANI/LDOs) were synthesized by a simple in situ oxidative polymerization. PANI/LDOs have been researched via various characterization technologies and used to remove hexavalent chromium (Cr(VI)) from aqueous solutions. The influences of adsorption kinetics, isotherms, pH, coexisting ion types and strength on Cr(VI) removal were systematically studied. The results indicated that the existence of LDOs reduced the accumulation density of PANI and enhanced the specific surface area, which is beneficial to absorb Cr(VI) by PANI/LDOs. Kinetic studies reveal that the Cr(VI) adsorption onto PANI/LDOs was well fitted by the pseudo-second-order model. The isotherms were well simulated by Langmuir model, and the maximum adsorption capacity of Cr(VI) on PANI/LDOs reached 409.77 mg/g at pH ∼ 2.0, which was superior to those of conventional adsorbents. Thermodynamic data revealed that the process of removing Cr(VI) was spontaneous and endothermic. The interaction mechanisms between PANI/LDOs and Cr(VI) were studied, indicating that Cr(VI) (HCrO₄^- and Cr₂O₇^2- were the main species when the aqueous solution pH 2) were reduced to Cr(III) through -NH-/=N- groups after uptaking to the protonated active sites of PANI/LDOs via electrostatic attraction. Furthermore, the PANI/LDOs composites can be regenerated and used repeatedly more than five cycles without significantly reducing in its adsorption capacity. All these results demonstrated that the fabricated PANI/LDOs possess great potentiality for Cr(VI)-containing wastewater treatment.

在这项研究中，聚苯胺/ Mg-Al层状双氧化物（PANI / LDOs）的有机-无机杂化材料是通过简单的原位氧化聚合反应合成的。已通过各种表征技术对PANI / LDO进行了研究，并将其用于去除水溶液中的六价铬（Cr（VI））。系统地研究了吸附动力学，等温线，pH，共存离子类型和强度对Cr（VI）去除的影响。结果表明，LDOs的存在降低了PANI的积累密度并增加了比表面积，这有利于PANI / LDOs吸收Cr（VI）。动力学研究表明，Cr（VI）在PANI / LDOs上的吸附与拟二阶模型非常吻合。等温线用Langmuir模型很好地模拟，在pH〜2.0时，Cr（VI）在PANI / LDOs上的最大吸附容量达到409.77 mg / g，优于常规吸附剂。热力学数据表明，去除Cr（VI）的过程是自发的且吸热的。研究了PANI / LDO与Cr（VI）之间的相互作用机理，表明Cr（VI）（HCrO₄ ^-和Cr ₂ ö ₇ ^2-为主要物种当水溶液的pH 2）分别降低为Cr（III）通过-NH - / =摄取到PANI的质子化的活性部位之后的N-基团/经由静电吸引的LDO 。此外，PANI / LDOs复合材料可以再生并重复使用超过五个周期，而不会显着降低其吸附能力。所有这些结果表明，所制备的PANI / LDO具有很大的潜力处理含Cr（VI）的废水。