Meter-scale fabrication of water-driven triboelectric nanogenerator based on in-situ grown layered double hydroxides through a bottom-up approach

High-performance water-driven triboelectric nanogenerators (WD-TENGs) that could collect energies from water droplets are of interest for both fundamental study of the energy conversion mechanism and practical perspective. Reported WD-TENGs are mainly based on synthetic polymer films which are of difficulty to achieve both ultralow surface energy and large-scale fabrication at the same time. Here, we demonstrate a bottom-up strategy to fabricate meter-scale WD-TENG by direct growing layered double hydroxide nanosheets perpendicularly on the metal substrate. With chemical modification, a nearly "friction free" triboelectric layer is achieved for better water energy harvesting. Furthermore, the energy conversion process is studied on the basis of the simulations proving that the electrostatic induction is the dominant mechanism. This approach could be easily scaled-up, and is thus a promising strategy to existing production method of WD-TENG and their based self-powered sensors.