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用乙酰丙酮还原氧化石墨制备得到石墨烯,其可在水、丙酮、N,N-二甲基甲酰胺等极性溶剂中超声分散,其中以水作为溶剂其分散性最好(浓度约为0.7g/L)。通过原子力显微镜(AFM)测定石墨烯的厚度为0.68nm,表明石墨烯是单层。红外光谱(IR)和紫外可见光谱(UV-Vis)数据表明乙酰丙酮被化学功能化修饰到石墨烯表面,且红外光谱中羧基峰的消失表明氧化石墨被乙酰丙酮还原。通过电感耦合等离子体发射光谱仪(ICP-AES)测定吸附后离子浓度,用Langmuir吸附等温式计算得到石墨烯对于Pb2+的最大吸附量为105.4mg/g,相关系数r为0.99958,Langmuir常数b为3.65。研究表明:石墨烯对水溶液中重金属Pb2+离子具有优异的吸附性能,这主要归因于石墨烯的巨大比表面积和乙酰丙酮分子对Pb2+离子的强络合能力。
Graphene is prepared by reduction of graphite oxide with acetylacetone, which can be ultrasonically dispersed in polar solvents such as water, acetone and N, N-dimethylformamide. The best dispersibility is water (solvent: about 0.7 g / L). The thickness of graphene was determined by atomic force microscopy (AFM) to be 0.68 nm, indicating that graphene is a monolayer. Infrared (IR) and ultraviolet-visible (UV-Vis) data indicate that acetylacetone is chemically functionalized onto the graphene surface and the disappearance of the carboxylate peak in the infrared spectrum indicates that the graphite oxide is reduced by acetylacetone. The ion concentration after adsorption was determined by inductively coupled plasma-atomic emission spectrometry (ICP-AES). The maximum adsorption capacity of graphene for Pb2 + was 105.4 mg / g, the correlation coefficient r was 0.99958 and the Langmuir constant b was 3.65 by Langmuir adsorption isotherm . The results show that graphene has excellent adsorption properties for heavy metal Pb2 + in aqueous solution, which is mainly due to the great specific surface area of graphene and the strong complexation ability of the acetylacetone molecule to Pb2 +.