Enhanced evaporation-induced electricity generation of reduced graphene oxide membrane via graphene quantum dots

Evaporation-induced electricity generation (EIEG) presents a promising alternative to conventional energy conversion technologies by enabling the harvesting of green energy from water. In this study, graphene quantum dots (GQDs) were employed to enhance the performance of EIEG in two-dimensional (2D) reduced graphene oxide (RGO) membranes. The GQDs rich in oxygen-containing functional group enhanced the hydrophilicity of the RGO matrix and modified the laminar structure of the RGO membrane, thereby facilitating the transport of water molecules. Moreover, GQDs with a high surface charge reduced the internal resistance of the composite membrane, resulting in an increased open-circuit voltage of 0.12 V and a short-circuit current of 1.11 μA, compared to the pristine RGO. Additionally, the effects of GQDs content, ambient humidity, and evaporating solvent on the performance of EIEG in GQDs/RGO (G-RGO) membrane were investigated. This study demonstrates the key role of GQDs in enhancing the performance of EIEG in graphene-based materials, providing crucial insights for material design.