Abstract

Oil–water emulsions are a considerable hazard to the environment, ecology, and human health, if not appropriately treated. This study proposes a self-powered and efficient triboelectric dehydrator (TED) based on a wind-driven freestanding rotary triboelectric nanogenerator (FR-TENG) to separate water-in-oil emulsions. This TED can form a high-voltage electric field in the emulsion when the FR-TENG is driven by mechanical energy. The dehydration performance of the TED is analyzed in detail through multiphysics-coupled models and experiments. It is found that the TED can dehydrate water-in-oil emulsions with a wide range of initial moisture contents. In particular, even when the initial moisture content is 60%, which is near the phase inversion concentration of the emulsion, the dehydration rate of the TED can still reach 99.41%. In addition, the performance of TED is demonstrated in a simulated situation of wind, suggesting that the present TED has great potential application for separating oil–water emulsions by harvesting environmental energy.