Mechanistic insight into electricity generation from moving ionic droplets on graphene

Recent experiments have demonstrated that moving water droplets on polymer-supported graphene can generate electric voltages in graphene. Here, we perform a multi-scale analysis the mechanism of generated basis an interplay among substrate, and ionic water. We find attraction ions by substrate dipoles drives charge redistribution graphene, forming triple layer (ETL) at water/graphene/substrate interface, made ion fixed image counterion As droplet moves dynamic formation ETL its front end flow Using Langmuir adsorption theory combined with ab initio calculations, determine concentration estimate amount each draw Then, current is formulated terms concentration, velocity, thickness density dipoles, which well reproduces experimentally measured currents These results underscore importance tailoring optimizing performance devices for energy harvesting promoting practical applications.