Effects of electrode placement position and tilt angles of a platform on voltage induced by NaCl electrolyte flowing over graphene wafer

Abstract

The extraction of energy from water in the natural environment has attracted significant interest in energy-harvesting applications in recent years. This study investigates the effects of the electrode placement position and the tilt angle of a platform on the voltage induced by a flow of aqueous NaCl electrolyte solution over a two-dimensional graphene wafer. It is shown that an orthogonal arrangement of the electrodes relative to the electrolyte flow direction maximizes the induced voltage. Further experiments are performed in which the graphene wafers are positioned such that the electrolyte flows over the short and long sides of the electrodes, respectively. The results show that the higher voltage response is obtained when the electrolyte flows through the long side of the electrodes. Finally, an investigation is performed into the voltage induced for various tilt angles from 20° to 60° of the graphene wafers placed on a platform. The charging and discharging time are revealed from experiments for the first time for various tilt angles. Based on the cases studied, the 45° tilt angle induces the highest voltage. Overall, the results presented in this study provide a useful insight into the optimal electrode placement position and tilt angle of a platform for graphene energy harvesting from aqueous sodium chloride solutions.