Method for production of carbon nanofiber mat or carbon paper

Method for the preparation of a non-woven mat or paper made of carbon fibers， the method comprising carbonizing a non-woven mat or paper preform (precursor) comprised of a plurality of bonded sulfonated polyolefin fibers to produce said non-woven mat or paper made of carbon fibers. The preforms and resulting non-woven mat or paper made of carbon fiber， as well as articles and devices containing them， and methods for their use， are also described.