Fabrications And Characterizations Of Co-doped 3D Graphene-based Materials And Their Applications

Three-dimensional graphene,which built from two-dimensional graphene nanosheets,has attracted tremendous interest in recent years.3D graphene retained the advantages of 2D graphene nanosheets,such as large surface area,extraordinary electron mobility,good thermal conductivity and high mechanical properties.2D graphene nanosheets were usually compromised by restacking and aggregation,3D graphene overcome this obstacle because of its stable three-dimensional structure.Therefor,the 3D graphene has better propertis of recycling and applications.Based on the development of 3D graphene,this dissertation launched a series of studies on the preparation of co-doped 3D graphene with attractive properties and their reliable applications.There are five chapters in this dissertationChapter 1,the studies on 3D graphene have been summarized,including synthetic methods,physicochemical properties,and their applications in different fields.Chapter 2,a phosphorylethanolamine-functionalized graphene foam(PNGF)has been proposed as an active material for water purification.Benefiting from its abundant hydrophilic portion,the PNGF is super-hydrophilic.It can absorb water,oils,organic dyestuff and heavy metal ions.Pb(II)and Cd(II)could be rapidly and efficiently absorbed within 10 min using the PNGF through a filtration model,which is obviously less time compared with the several hours or even longer time when employing the traditional shaking or stirring model.Chapter 3,the 3D graphene foam was functionalization by the important nutrient molecule taurine(a-NSGF).A-NSGF has a stable three-dimensional structure and good electrical conductivity.The high temperature in the process of annealing allowed the N/S atoms to enter into the graphene lattice,which improves its electrocatalytic activity greatly.We used a-NSGF to construct a biosensor for H2O2 detecting without enzyme.The sensor is easy to prepare and preserve,and the detection activity is almost nondestructive in the long period of two months.Chapter 4,the cheap industrial reagent aminobenzene sulfonic acid was choosen as a surface modification agent.By adjusting the type and dosage of the functional reagent,and the preparation condition(such as pH value and the annealing temperature),N/S co-doped 3D graphene materials(SNGF)with different microscopic structure and chemical properties were prepared.Furthere more,the solid surface wettability of SNGF could be adjust by condition control.Chapter 5,current challenges and future perspectives for 3D graphene-based materials.