Harvesting energy from the ambient environment provides great promise in the applications of micro/nanodevices and self-powered systems. Herein, we report a novel energy-scavenging method where an ionic solution infiltrating into a three-dimensional graphene (3DG) membrane can spontaneously generate electricity under ambient conditions. A constructed 3DG nanogenerator (3DGNG) with an effective size of 0.5 × 2 cm can produce a continuous voltage of ∼0.28 V and a remarkable output current of ∼62 μA. The voltage is higher than those generated from the interaction between water and carbon nanomaterials in previous research typically in the range of microvolts to millivolts. Moreover, we demonstrate the potential application of the 3DGNG by illuminating a liquid crystal display (LCD) directly with 10 3DGNGs in series. These results present a novel avenue for energy harvesting and show bright potential applications in small devices and self-powered systems.
Keywords: 3D graphene; capillary-driven flow; energy harvesting; self-powered system; streaming potential.