Synthesis And Properties Of 3D-graphene Based On Biomass

Three-dimensional(3D)graphene with excellent physical and chemical property has broad application prospect in the fields of energy and environment,and has attracted extension attention.Currently,3D-graphene is commonly synthesized by chemical vapor deposition(CVD)and reduction-assembly via graphene oxide method.However,due to complicated operation,and high production cost,these methods are difficult for the large-scale production of 3D-graphene.In this study,we develop a new,facile,versatile,and gram-scale "co-precipitation-carbonization" strategy,where,water-soluble biomass is used as carbon source,and inorganic salt as template.The cotton-like 3D graphene constituted of thin,transparent,wrinkled and interconnected nanosheets is yielded.First,different types of 3D-graphene are prepared by changing the type and quality of biomass,the kind of salt and solvent and the temperature of thermal reduction,respectively.To explore the influence of temperature and biomass quality on their morphologies and degree of crystallinity,these 3D-graphenes are analyzed by SEM,TEM,Raman,XRD,XPS,BET,elemental analysis and FT-IR,respectively.Furthermore,the properties of the synthetic materials in terms of the photothermal conversion(PTC)efficiency to near-infrared light,the adsorption,and the electrical properties are investigated.The experimental results are shown as following:1)This "co-precipitation-carbonization" method is a simple,universal,low cost,and gram-scale strategy.3D-graphene materials with similar structure and morphology can be synthesized by changing the relative content of protein to salt,the type of salt,carbon source and solvent,respectively.Moreover,the crystallinity of the material becomes better with the increase of the treatment temperature.And when the temperature reaches 1500℃,the best crystallinity(C-BSA-1500℃)is achieved.2)The resulting material(C-BSA-1500℃)displays unprecedented PTC efficiency(h=79.76%)of infrared radiation at a power density of 1.5 W·cm-2(808nm).3)The resulting material(C-BHL-600℃)also exhibits excellent adsorption capacities for methyl violet(350.0 mg·g-l),methylene blue(360.0 mg·g-1),paraquat(69.5 mg·g-1)and sulfonamides(35.6 mg·g-1),and fast kinetics,in which target dye can be instantaneously removed from the solution.4)Due to highly conductivity(3.4×103 S·m-1),the resulting material(C-BSA-1400℃)can deliver a high specific capacity of 252.5 mAh·g-1 at 0.2 A·g-1 and admirable cycling stability that the specific capacity is 250.5 mAh·g-1 at 100th cycle.In conclusion,the materials(3D-graphene)with excellent photothermal conversion,adsorption and electrical properties are synthesized by a new,simple and universal method,and are expected to be used in the fields of seawater desalination,water purification and batteries.