According to the present disclosure, a method of fabricating a metal-carbon fibrous structure is provided. The method comprises the steps of: (a) forming a fibrous support structure comprising composite nanocrystals and polymeric fibers, wherein each of the composite nanocrystals comprises metal ions connected by organic ligands; (b) growing the composite nanocrystals on the fibrous support structure; and (c) subjecting the fibrous support structure of step (b) to carbonization to form the metal-carbon fibrous structure, wherein the metal-carbon fibrous structure comprises metal nanoparticles derived from the composite nanocrystals comprising metal organic framework (MOF), particularly zeolitic imidazolate framework (ZIF). A metal-carbon fibrous structure comprising carbon based fibers arranged to form a porous network and the carbon based fibers are doped with metal nanoparticles, wherein the carbon based fibers have surfaces which comprise graphitic carbon, is also disclosed herein.