Three-dimensional graphene content supercapacitor production

Graphene is a unique material in terms of its electrical, thermal and mechanical properties. In recent years, it has been used extensively in sensors, photodetectors, solar panels, energy storage devices and catalysis research. It is aimed to homogeneously distribute 2 dimensional (2D) graphene layers into polymers and to use these structures in electromagnetic coating, optoelectronics and sensor technology, especially in energy applications. CVD method and Hummers method are generally used in GF production. The first of these methods is costly and requires low pressure and expensive inert gases. The second method requires the use of harmful toxic substances, and the resulting product is not sufficiently pure. But parameters such as the inhomogeneous distribution of graphene sheets and the tendency to assemble among them, high interlayer resistance, the use of graphene has been significantly limited.In this study, it is aimed to produce a three-dimensional (3D) graphene foam structure in order to eliminate this problem. For this purpose, firstly, solutions containing 2D graphene structures were obtained by electrochemical stripping method. Then, the hydrothermal method was used to stack these structures on a metal framework to form a three-dimensional structure. These structures were used as supercapacitor electrodes without the need for any organic binders or conductivity enhancers. Among the structures obtained by the hydrothermal method, the best specific capacitance was obtained as 280 F g at a constant 1 A/g for 2000 continuous charge and discharge cycles. Among the samples electrodeposited at different times, the graphene electrodeposited electrode for 10 min showed the best electrochemical performance. The maximum capacitance value is observed 970 F/g at constant 20 A/g for 2500 continuous charge and discharge cycles.In addition, a preliminary study was carried out for the use of the produced 3D graphene structure as a humidity sensor.