One artist has an idea to using an electrostatic field generated by copper coils to attract smog particles and remove the smog from the air, basically allowing it to be vacuumed up.
The artist, Daan Roosegard, is working with the mayor of Beijing to see if they can set up something like this in one of their parks, and to put the idea to the test in a real-world application in a city that probably needs this more than any other city I can think of.
More at: Huffington Post