Superhydrophobic Cellulose Paper-Based Triboelectric Nanogenerator for Water Drop Energy Harvesting

The high-efficiency conversion of water drop mechanical energy into electrical energy has always been an urgent issue in the development and utilization of raindrop energy. In this work, a novel drum-like triboelectric nanogenerator (D-TENG) with robust self-cleaning superhydrophobic features is developed to harvest water drop energy. An elastic superhydrophobic cellulose paper is created by spray-coating nanofumed silica dispersed in a thermoplastic elastomer solution, followed by treatment with triethoxy-1H,1H,2H,2H-tridecafluoro-n-octylsilane. When raindrops hit the D-TENG surface, the superhydrophobic cellulose paper will vibrate and periodic contact and separation with polytetrafluoroethylene will occur to generate electricity. The results demonstrate that when a 6 mm water drop falls from a height of 2.5 m and hits the D-TENG, the generated voltage output can reach a peak of 21.6 V and charge transfer of 10 nC. The output power of the D-TENG can reach 16 mu W per droplet, which is more than 13.3 times that generated from the previous TENGs based on the electrostatic induction of water droplets. These results indicate that the superhydrophobic cellulose paper-based D-TENG is potentially a strong candidate for harvesting energy from raindrops, thereby making it a promising sustainable energy source for next-generation electronics.