The Effects Of Processing Technology And Oxygen Content On Rolled Copper Foil For The Manufacture Of Graphene

Graphene has good mechanical,thermal,optical and electrical properties,and has broad application prospects in many fields,such as electronics,information,energy,materials,and biomedicine.At present,methods for preparing graphene include mechanical stripping,chemical vapor deposition(CVD),oxidation reduction,etc.Graphene is prepared by chemical vapor deposition based on rolled copper foil with large area,high mass,layer-controlled synthesis and low cost.However,the graphene prepared by chemical vapor deposition is attached to the surface of rolled copper foil.The surface defects and grain boundary of rolled copper foil will accelerate the nucleation of graphene,which will have an adverse effect on the deposition and growth of graphene.Therefore,the rolled copper foil for the preparation of graphene requires good surface quality and larger grain size.However,the factors in the process of rolled copper foil production such as deformation rate,oxygen content and heat treatment process will influence the surface quality and the size of recrystallized grain.In this paper,the effects of heat treatment process,oxygen content and deformation rate on surface quality and recrystallization behavior of rolled copper foil for graphene were studied by means of metallographic observation,scanning electron microscopy,EDS spectroscopy,tensile and hardness determinations.And the production process of the rolled copper foil for the preparation of graphene was optimized.The research content and results are as follows:(1)The effects of pre-annealing and high-temperature annealing on surface quality,microstructure and grain growth of rolled copper foil were investigated.The results showed that with the increase of pre-annealing temperature of rolled copper foil,the surface of the rolled copper foil oxidizes gradually,and the surface roughness remains unchanged and then increases gradually;At the same time,the pre-annealing temperature also affects the grain size of the annealed copper foil at high temperatures.With the increase of the pre-annealing temperature,the grain size at the high-temperature annealing increases gradually and then remains unchanged;The best pre-annealing temperature of the copper foil for graphene is the recrystallization temperature;In the high-temperature annealing process,the grain size increases gradually with the increase of the high-temperature annealing temperature.When the annealing temperature exceeds 1050°C,more pits appear on the surface of the copper foil;With the increase of high-temperature annealing holding time,the grain size of copper foil increases gradually at first,and then remains unchanged basically.If the holding time is too long,more dot-like particles will appear on the surface of the copper foil;The optimum temperature for high-temperature annealing of the rolled copper foil for graphene is 1000°C,and the optimal holding time is 40 min.(2)The effects of oxygen content on rolled copper foil were studied.The results showed that with the increase of oxygen content in the rolled copper foil,the second phase particles appear gradually,which will form a small scratch on the surface,but have little effect on the surface roughness of the copper foil;When the oxygen content increases from 10 ppm to 50 ppm,the recrystallization temperature decreases from 245? to 160?.When the oxygen content increases in the range of 50~130ppm,the recrystallization temperature remains unchanged essentially;The oxygen content has little effect on the recrystallization nucleation rate during the pre-annealing process,and the grain size is unchanged basically after high-temperature annealing;The optimum oxygen content of the rolled copper foil for graphene is 50 ppm.(3)The effects of deformation rate on the rolled copper foil were studied.The results showed that with the increase of deformation rate,the indentation of ravine on the surface of copper foil disappears gradually,and the density of oil pit indentation increases.The copper surface roughness decreases firstly,and then increases;With the increase of the deformation rate,the recrystallization temperature decreases from 175? to 120? gradually;After high-temperature annealing process,the grain size of copper foil decreases with the increase of deformation rate;The optimum deformation rate of the rolled copper foil for graphene is 67%.