Triboelectric interface and droplet behavior regulation toward high-performance liquid-solid nanogenerator

Droplet-based nanogenerators show great potential for harvesting environmental water energy, yet their performance is often limited by low charge generation and transfer efficiency at the liquid-solid interface. Here, we develop a high-output liquid-solid triboelectric nanogenerator (LS-TENG) with surface functionalized triboelectric layer, where a dual-effect synergistic modification interface of nanostructure and fluorine-containing functional group grafting is constructed. This strategy significantly optimizes the droplet's dynamic behavior and one droplet can achieve a power output of 1.4 mW, which is about 30 times higher than that of the original device. Meanwhile, theoretical model of droplet spreading-retraction dynamics is established, the influence of triboelectric interface parameters on droplet behavior is analyzed, and the mechanism by which droplet expansion-contraction and motion behaviors regulate output performance is revealed. The LS-TENG eventually achieves a liquid-solid energy conversion efficiency of 12% and exhibits good energy supply capability for small electronics. This work proposes an effective surface engineering for enhancing droplet power generation and clarifies the mechanism of droplet contact dynamic behavior regulating triboelectric output, providing an inspired pathway to develop high-performance droplet energy harvesters.