Controllable Preparation Of Graphene Composite Membrane And Its Separation Performance For Hydrogen/Deuterium Water

In order to meet the country’s energy needs and achieve the carbon neutrality goal of greenhouse gas emissions,my country will continue to maintain a high-speed development of nuclear energy,a clean energy source.Nuclear energy involves the processing of liquids containing the radioactive element tritium（T）.At present,there are many ways to treat tritium-containing wastewater,but generally the energy consumption is large and the process is complicated.Membrane distillation（MD）technology has attracted great interest due to its simple process,convenient operation,energy saving and environmental protection.The separation of deuterium and tritium can be accomplished by membrane technology.Graphene oxide（GO）is a typical two-dimensional material,and studies have shown that GO films can be used to separate hydrogen isotopes.However,the poor stability and low permeability of GO membranes greatly hinder the application of GO membranes.In this paper,new methods are proposed to explore and improve the work of GO membranes in hydrogen isotope separation.Preparation of different types of GO-like two-dimensional materials,such as molybdenum disulfide（Mo S₂）and boron nitride（BN）,through in-depth study of different types of functionalized GO films and monolayers of GO with different sheet sizes,to explore functional groups and sizes.The effect of sheet diameter on the properties of GO films.Mixing GO with multi-walled carbon nanotubes（MWCNTs）and adjusting the interlayer spacing is used to improve the overall performance of the films.The main research results are as follows:（1）When preparing two-dimensional composite films of GO-like materials,the van der Waals-like heterostructure composite films of GO,Mo S₂ and BN materials were further studied.The results show that Mo S₂ and BN membranes can also be used for membrane distillation to separate hydrogen isotopes,and BN membranes have higher permeation flux,reaching the 1.022 kg·m^-2·h^-1,and the separation factor was also 1.044.（2）The effects of different functionalized GO films and sheet diameters on the properties of GO films were compared.Using amino graphene,carboxyl graphene and reduced graphene oxide to compare with GO membranes,the experimental results show that amino graphene has a higher permeation flux,with an average of 0.855 kg·m^-2·h^-1.The highest average separation factor of GO membrane was 1.048.In the membrane distillation experiments using monolayer graphene oxide,GO-01 has a higher permeation flux with an average of0.966 kg·m^-2·h^-1.GO-03 was shown to have a higher separation factor with an average of1.041.（3）The composite membrane was prepared by mixing multi-walled carbon nanotube（MWCNTs）dispersion with GO dispersion.The experimental results showed that the maximum permeation flux was obtained when the ratio of GO to MWCNTs was 1:3 is 0.947kg·m^-2·h^-1.When the MWCNTs membrane with PTFE as the base membrane was used,the separation factor was up to 1.049.The layered structure has an effect on the performance when preparing the van der Waals-like heterostructure membrane.Experimented and found that the fast evaporation method can be used to select the membrane simply and effectively,which is faster and more convenient than the membrane distillation method to select the membrane with the best performance.It provides a simple and effective way for the next quick screening.