Microporous carbon–nitrogen fibers from keratin fibers by pyrolysis

A two‐step pyrolysis method was developed for poultry keratin fibers to convert them into high temperature resistant and adsorbent fibers while retaining their original physical appearance and affine dimensions. Nearly all accessible pores in the microporous pyrolyzed chicken feather fibers (PCFF) have a diameter less than 1 nm and could be used in applications, such as adsorption, hydrogen storage, and separation of small gas molecules. An intermolecular crosslinking mechanism in the first step of pyrolysis at 215°C for 24 h provided an intact fibrous structure with no subsequent melting. The second step of the pyrolysis at 400–450°C for 1 h resulted in a microporous material with a narrower pore size distribution than commercial activated carbons. Surface and bulk characterization techniques including XPS, total carbon–nitrogen, and FTIR were utilized to examine property changes occurring during the two pyrolysis steps. A partially cyclic carbon–nitrogen framework (carbon/nitrogen ratio = 2.38) supported by double and triple bonds, and oxygen functionalities is the suggested structural model for the PCFF.