Efficient removal of particulate matter (PM) is the major goal for various air cleaning technologies due to its huge impact on human health. Here, a washable high-efficiency triboelectric air filter (TAF) that can be used multiple times is presented. The TAF consists of five layers of the polytetrafluoroethylene (PTFE) and nylon fabrics. Compared with traditional electrostatic precipitator, which requires a high-voltage power supply, the TAF can be charged by simply rubbing the PTFE and nylon fabrics against each other. The electrical properties of the TAF are evaluated through the periodic contacting-separating of the PTFE and nylon fabrics using a linear motor, and an open-circuit voltage of 190 V is achieved. After charging, the TAF has a removal efficiency of 84.7% for PM 0.5 , 96.0% for PM 2.5 , which are 3.22 and 1.39 times as large as the uncharged one. Most importantly, after washing several times, the removal efficiency of the TAF maintains almost the same, while the commercial face mask drops to 70% of its original efficiency. Furthermore, the removal efficiency of the PM 2.5 is very stable under high relative humidity. Therefore, the TAF is promising for fabricating a reusable and high-efficiency face mask.

We developed a high-efficiency rotating triboelectric nanogenerator (R-TENG) enhanced polyimide (PI) nanofiber air filter for particulate matter (PM) removal in ambient atmosphere. The PI electrospinning nanofiber film exhibited high removal efficiency for the PM particles that have diameters larger than 0.5 μm. When the R-TENG is connected, the removal efficiency of the filter is enhanced, especially when the particle diameters of the PM are smaller than 100 nm. The highest removal efficiency is 90.6% for particles with a diameter of 33.4 nm and the highest efficiency enhancement reaches 207.8% at the diameter of 76.4 nm where the removal efficiency enhanced from 27.1% to 83.6%. This technology with zero ozone release and low pressure drop offers an approach for air cleaning and haze treatment.