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

• Published in: Applied surface science 2018-12, Vol.462, p.65-72
• Main Authors: Xiang, Qin, Li, Sha, Zou, Xuefeng, Qiang, Yujie, Hu, Bingbing, Cen, Yuan, Xu, Chuanlan, Liu, Lijun, Zhou, Yan, Chen, Changguo
• Format: Article
• Language: English
• Subjects: Acetylene black; Defect-projecting and heteroatoms-doping; Metal-free electrocatalyst; Porous structures; Sulfur template
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2018.08.022

[Display omitted] •Sulfur was deposited in situ on oxygen-functionalized acetylene black, and directly employed as both template and sulfur source for assembling OAB@S-N.•The synergistic effects between the defect-projecting and heteroatoms-doping boosted the electrocatalytic activity of the OAB@S-N.•The specific doping at defective sites affording a striking long-term stability for this metal-free electrocatalyst. 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.