How do carbon filters work?

If you take a small bent tubing and put a fan on one end and a nylon sock on the other then a bucket of carbon scott taped on..is that any different that then using a bucket to hold the carbon that can breathe? .. aka: is the carbon filtering the air then releasing it, or is it suppose to stay in there and like adsorb into the carbon?
What the best DIY carbon filter you found?

ALSO!
Can you just put a fan and pipe - carbon filter in your closet? I have no exhaust I just open the door every few hours
If carbon adsorbs odor why cant a piece of paper with activated carbon on it with a fan blowing to it work?

carbon paper does work just not well ! its not thick enough your better off getting some thin steel mesh just like on the budget filters and sort of copy it ! its round so there is lots of surface area and only about an inch, inch n a half of carbon.
just make sure you get the right carbon ! there are numerous threads on this subject ! its not as cheap as you think though !
plus apparently the rougher stuff is better than pellets !
you also need it to "blow" or "suck" through it not over it.
works the same as a water filter basically even uses the same carbon as some !!