The ocean, with its highly variable and complex meteorological conditions, harbors enormous renewable resources. Triboelectric nanogenerators (TENGs), which possess unique advantages, show exciting prospects in water wave energy collection. How to design and optimize TENGs to cover all characteristic water wave energies and achieve efficient energy utilization is emergent. In this paper, we carefully designed and fabricated a columnar multi-layer sliding TENG (CMLS-TENG) that can harvest water wave energy independent of wave height and direction. Drive rods with a hollow acrylic spherical shell were introduced to deliver wave energy, ensuring that the CMLS-TENG can work in all directions from 0° to 360°. Based on the sliding structure, switching the optimized CMLS-TENG is independent of wave heights. The optimized CMLS-TENG can achieve a total power density of 730 mW/m³ at a wave height of only 4.8 cm regardless of wave direction, which can illuminate multiple light-emitting diodes (LEDs) to provide lighting and provide power to a watch and a hygrometer for temperature and humidity monitoring. This work provides new choices and hopes for the effective collection of full-range water wave energy.

Interface functional groups play an essential role in regulating the electrical properties of bulk materials. In this work, we designed a novel strategy to explore a new way to enhance triboelectric performance by regulating the functional groups between nano-fillers and polymer matrix without obvious changes in the dielectric constant. The silica nanoparticles (SNPs) modified perfluoro-silane coupling agents (PFSCAs) with different chain lengths were added to the polyvinylidene difluoride to regulate the transferred charge density (TCD) of triboelectric nanogenerators (TENGs). When the doping concentration of perfluorodecyl modified SNPs is 2.25 wt.%, the nanocomposite film based TENG exhibits the maximum TCD of 166 μC/m² and power density of 3.12 W/m² which are 6 times and 39 times as big as those of pure polyvinylidene difluoride (PVDF) film. The charge accumulation and decay process show that interface functional groups dominate the performance of TENGs. Then, a Fermi level model is proposed and why the TCD could be regulated by the concentration of nanoparticles in bulk materials is explained. This work provides a new concept for understanding the performance of TENG independent dielectric constant and points out a new direction for enhancing TENG’s performance, since wealthy functional groups with selectivity are applicable.