Self-assembly porous metal-free electrocatalysts templated from sulfur for efficient oxygen reduction reaction

Abstract

Acetylene black (AB) was exfoliated and functionalized through a single-pot method then be assembled to a novel porous carbon material by utilizing sulfur as both template and sulfur source. The defect-rich structures of the obtained AB play a critical role in providing more appropriate sites for sulfur atom doping. After a pyrolysis process in the presence of melamine as N doping agent, the sulfur template was decomposed and yielded the N,S-codoped porous carbon material with additional porosity. The synergistic effects between the defect-projecting and heteroatoms-doping boost the activity of electrocatalysts in terms of the enhanced oxygen reduction efficiency and optimized kinetic process, both are better than that of commercial Pt/C. And the improved reactivity between carbon atoms and heteroatoms as well as sulfur and nitrogen atoms greatly suppress the loss of active ingredient of the catalyst, the mechanism yields a striking long-term stability for the unique metal-free OAB@S-N electrocatalyst.