High-performance triboelectric nanogenerators for self-powered, in-situ and real-time water quality mapping

Water pollution is one of the most severe environmental issues nowadays. For sustainably and autonomously monitoring water quality, in-situ self-powered sensing systems which can harvest local wave energy are highly desired. Here, a high-performance tandem disk triboelectric nanogenerator (TD-TENG) for self-powered water quality monitoring is demonstrated. By surface modification and optimized design, a radial grating structure which can be effectively agitated by slow water waves is realized, boosting the peak and average power of wave-energy-harvesting TENG devices to 45.0 mW and 7.5 mW respectively, which are roughly 35 and 24 folds of the typical ball-shell structured device. The average power density reaches 7.3 W m⁻³, setting up a new record. The short-circuit current is greatly enhanced to 11 mA through a facile power management circuit. The high output enables a self-powered total dissolved solids testing system, which can be scaled up into networks for in-situ, real-time mapping water quality in a large area. The TD-TENG as a high-power wave energy harvesting device also opens up an avenue to solve the bottleneck of power supply for versatile sensing platforms that need to work autonomously in water, providing a fundamental technology for smart environmental and ocean science.