A water collection system with ultra-high harvest rate and ultra-low energy consumption by integrating triboelectric plasma

Abstract

In many areas of the world, fog harvesting could be a sustainable solution to water shortage. However, due to the limitation of deposition efficiency and shedding rate of the droplets, the fog/water conversion efficiency is extremely low. Here, a self-powered fog harvesting system by integrating triboelectric plasma is developed. Taking the advantage of space charges injected through triboelectric plasma into the fog flow, tiny water droplets deposit onto the collecting mesh with unprecedentedly high efficiency. By endowing the mesh with superhydrophobicity, water collected on it sheds off quickly, which guarantees fast regeneration of the fog collection system. The final water harvest rate reaches 1311.79 g/(m2·min), about 3.28 times of the maximum value reported in literatures, with the fog/water conversion efficiency of 55.5%. More importantly, the energy consumption is minimized to 0.052 kWh/m3, far lower than ~ 3–5 kWh/m3 energy consumption in the frequently-used reverse-osmosis desalination technique and ~ 2 kWh/m3 in the newly-developed high voltage power supply-assisted fog harvesting system. A physical model based on the synergistic effect of triboelectric plasma and surface wettability is proposed to illuminate the mechanism. This self-powered efficient fog harvesting system provides great promise to relieve local water scarcity energy-effectively.