MnO_(2)/Ti_(3)C_(2)T_(X)复合剂对水中U(VI)的吸附性能与机制  

Adsorption performance and mechanism of MnO_(2)/Ti_(3)C_(2)T_(X)composite towards U(VI)in water

作　　者：周国霖 谢水波 胡恋[3] ZHOU Guolin;XIE Shuibo;HU Lian(School of Civil Engineering,University of South China,Hengyang 421001,China;Hunan Provincial Key Laboratory of Pollution Control and Resources Technology,University of South China,Hengyang 421001,China;Hunan Prospecting Designing&Research General Institute for Agriculture Forestry&Industry,Changsha 410007,China)

机构地区：[1]南华大学土木工程学院,衡阳421001 [2]南华大学污染控制与资源化技术湖南省重点实验室,衡阳421001 [3]湖南省农林工业勘察设计研究总院,长沙410007

出　　处：《复合材料学报》2024年第11期6014-6025,共12页Acta Materiae Compositae Sinica

基　　金：国家自然科学基金(11475080);湖南省自然科学基金(2021JJ30579)。

摘　　要：针对Ti_(3)C_(2)T_(X)纳米片层易堆叠和吸附位点少的不足,采用水热法制备了MnO_(2)/Ti_(3)C_(2)T_(X)复合剂。通过单因素试验探讨铀的初始浓度、投加量、pH值、时间和共存离子对其吸附U(VI)的影响,采用现代表征手段分析MnO_(2)/Ti_(3)C_(2)TX的表面性质及吸附U(VI)的作用机制。试验结果表明:在U(VI)初始浓度5 mg·L^(−1)、MnO_(2)/Ti_(3)C_(2)TX投加量为0.1 g·L^(−1)、温度303 K、pH值为6时,30 s内U(VI)浓度降至0.41 mg·L^(−1),30 min后吸附达到平衡,其对U(VI)的吸附率达99.15%,吸附容量为49.58 mg·g^(−1)。经过5次循环后,MnO_(2)/Ti_(3)C_(2)TX对U(VI)的吸附效率仍保持在96.3%,具有良好的可再生利用性。整个吸附过程为自发吸热过程,符合拟二级动力学模型和Freundlich等温线模型。BET分析表明MnO_(2)/Ti_(3)C_(2)T_(X)的比表面积达318.3 m^(2)·g^(−1),较Ti_(3)C_(2)T_(X)高55.9倍。FTIR和XPS分析表明MnO_(2)/Ti_(3)C_(2)T_(X)对U(VI)吸附主要是表面含氧基团与铀的配位络合。To address the shortcomings of Ti_(3)C_(2)T_(X)nanosheets,which tend to stack and have limited adsorption sites,a MnO_(2)/Ti_(3)C_(2)T_(X)composite was prepared using the hydrothermal method.The influence of uranium initial concentration,dosage,pH,time,and interfering ions on U(VI)adsorption was investigated through single-factor adsorption experiments.Modern characterization techniques were employed to analyze the surface properties of MnO_(2)/Ti_(3)C_(2)T_(X)and the mechanism of U(VI)adsorption.Experimental results revealed that with an initial U(VI)concentration of 5 mg·L^(−1),MnO_(2)/Ti_(3)C_(2)T_(X)dosage of 0.1 g·L−1,and a temperature of 303 K,pH of 6,the U(VI)concentration dropped to 0.41 mg·L^(−1)within 30 s.Adsorption equilibrium was reached after 30 min,with an adsorption rate of 99.15%and an adsorption capacity of 49.58 mg·g^(−1).After five cycles,the adsorption efficiency of MnO_(2)/Ti_(3)C_(2)T_(X)remained at 96.3%,demonstrating its potential for regeneration and reuse.The entire adsorption process was endothermic and spontaneous,fitting the pseudo-second-order kinetic model and the Freundlich isotherm model.BET analysis showed that the specific surface area of MnO_(2)/Ti_(3)C_(2)T_(X)reached 318.3 m^(2)·g^(−1),which is 55.9 times higher than that of Ti_(3)C_(2)T_(X).FTIR and XPS analyses indicated that the primary mechanism of U(VI)adsorption on MnO_(2)/Ti_(3)C_(2)T_(X)is the coordination complexation between surface oxygen-containing groups and uranium.

关 键 词：Ti_(3)C_(2)T_(X) MXene 二氧化锰 吸附 铀 

分 类 号：TQ424[化学工程] X703[环境科学与工程—环境工程] TB332[一般工业技术—材料科学与工程]