二维材料复合质子膜的制备及其氕氚分离性能研究

Preparation of two-dimensional material composite proton exchange membrane and its performance in protium-tritium separation

采用溶液浇铸法分别制备了Graphene-Nafion和hBN-Nafion 2种二维纳米复合质子交换膜,利用XRD､ATR-FT-IR和SEM对复合膜的结构及微观形貌进行表征,并对复合膜的离子交换容量､质子电导率､机械性能和热稳定性进行测试,结果表明,Graphene和hBN纳米片均匀地分散于Nafion基体内部。相较于重铸Nafion膜(空白对照样品),复合膜的离子交换容量､质子电导率以及机械性能均有不同程度的提升,特别是在掺入质量分数为0.50%时,Graphene-Nafion和hBN-Nafion复合膜的质子传导性能约为重铸Nafion膜的1.25倍和1.14倍。通过对比Graphene-Nafion和hBN-Nafion 2种复合膜的氕氚分离性能发现,在初始氚水比活度为3.51×10^(7)Bq/L时,持续电解超过60 h,2种复合膜的氕氚分离系数分别为5.73和8.46,氚回收率分别为78.53%和85.35%,表明hBN-Nafion复合膜具有更好的氕氚分离性能。

Graphene-Nafion and hBN-Nafion,two kinds of two-dimensional nanomaterial composite proton exchange membranes,are prepared via the solution casting method,and characterized by means of XRD,ATR-FTIR and SEM.The ion exchange capacity,proton conductivity,mechanical properties,and thermal stability of the composite membranes are tested.It is indicated by the results that graphene and hBN nanosheets uniformly disperse inside Nafion matrix.The ion exchange capacity,plasmonic conductivity,mechanical properties and thermal stability of the composite membranes are better than the recast Nafion membrane.In particular,the proton conduction properties of Graphene-Nafion and hBN-Nafion composite membranes both at a doping amount of 0.50 wt%are about 1.25 and 1.14 times those of recast Nafion membranes.Through comparing the protium-tritium separation performance of Graphene-Nafion and hBN-Nafion composite membranes,it is found that the protium-tritium separation coefficients of the two composite membranes are 5.73 and 8.46,respectively,and the tritium recoveries are 78.53%and 85.35%,respectively when the continuous electrolysis has been performed for over 60 h at an initial tritium water specific activity of 3.51×10^(7)Bq·L^(-1),indicating that hBN-Nafion composite membrane has better protium-tritium separation performance.