磁性介孔TiO2/氧化石墨烯复合材料的制备及其对U(VI)的吸附学术资讯

《复合材料学报》优先在线发表论文。

摘要：以氧化石墨烯(GO)、纳米Fe3O4、钛酸四丁酯(TBOT)为原料，合成了磁性介孔TiO2/氧化石墨烯(Fe3O4@TiO2/GO)复合材料，用其处理浓度为10 mg·L-1的含U(VI)废水。研究了Fe3O4@TiO2/GO复合材料中GO含量、溶液初始pH、Fe3O4@TiO2/GO投加量、反应时间、U(VI)初始浓度及共存离子对U(VI)吸附的影响。结果表明：在pH值为6，GO质量分数为60wt%，Fe3O4@TiO2/GO投加量为10 mg的条件下，Fe3O4@TiO2/GO对U(VI)的吸附效果最佳，较同等条件下磁性介孔TiO2(Fe3O4@TiO2)和GO单独作用时吸附量分别高10.99 mg·g-1、1.91 mg·g-1。Fe3O4@TiO2/GO对U(VI)的吸附，180 min即达到平衡，准二级动力学模型和Freundlich吸附等温模型能很好地描述其吸附过程。解吸实验表明，经5次吸附-解吸后，U(VI)的吸附率仍高达90.86%，说明Fe3O4@TiO2/GO具有较高的循环利用性能。

关键词：氧化石墨烯；磁性介孔TiO2；U(VI)；吸附；解吸；共存离子

Abstract: Magnetic mesoporous TiO2/graphene oxide composites (Fe3O4@TiO2/GO) were prepared by the synthesis of graphene oxide (GO), nano-ferroferric oxide (Fe3O4) and tetrabutyl titanate (TBOT), then the composites were used to treat U(VI)-containing wastewater at a concentration of 10 mg·L-1. The effects of mass fraction of GO in Fe3O4@TiO2/GO,initial pH of solution, the dosage of Fe3O4@TiO2/GO, reaction time, initial uranium concentration and coexisting ions on U(VI) adsorption by Fe3O4@TiO2/GO were investigated. The results show that Fe3O4@TiO2/GO has the best adsorption effect on U(VI) under the optimal condition, the pH value is 6, the mass fraction of GO is 60wt%, the Fe3O4@TiO2/GO dosage is 10 mg, under the same conditions, the adsorption capacity of U(VI) is 10.99 mg·g-1, 1.91 mg·g-1 higher than that of magnetic mesoporous TiO2(Fe3O4@TiO2) and GO, respectively. The adsorption results of Fe3O4@TiO2/GO composites are balanced at 180 min, and the pseudo-second-order kinetics model and the Freundlich adsorption isotherm model are good descriptions of the adsorption of Fe3O4@TiO2/GO on U(VI) process. The results of desorption experiments show that the adsorption efficiency of Fe3O4@TiO2/GO on U(VI) remains as high as 90.86% after 5 cycles of adsorption-desorption, indicating that Fe3O4@TiO2/GO has higher recycling performance.