Removal of Particulate Matter Emissions from a Vehicle Using a Self-Powered Triboelectric Filter.

Particulate matter (PM) pollution from automobile exhaust has become one of the main pollution sources in urban environments. Although the diesel particulate filter has been used in heavy diesel vehicles, there is no particulate filter for most gasoline cars or light-duty vehicles because of high cost. Here, we introduce a self-powered triboelectric filter for removing PMs from automobile exhaust fumes using the triboelectrification effect. The finite element simulation reveals that the collision or friction between PTFE pellets and electrodes can generate large triboelectric charges and form a space electric field as high as 12 MV/m, accompanying an open-circuit voltage of ∼6 kV between the two electrodes, which is comparable to the measured value of 3 kV. By controlling the vibration frequency and fill ratio of pellets, more than 94% PMs in aerosol can be removed using the high electric field in the triboelectric filter. In real automobile exhaust fumes, the triboelectic filter has a mass collection efficiency of ∼95.5% for PM2.5 using self-vibration of the tailpipe.