Toward enhanced activity of a graphitic carbon nitride-based electrocatalyst in oxygen reduction and hydrogen evolution reactions via atomic sulfur doping

• Published in: Journal of materials chemistry. A, Materials for energy and sustainability Vol. 4; no. 31; pp. 12205 - 12211
• Main Authors: Pei, Zengxia, Zhao, Jingxiang, Huang, Yan, Huang, Yang, Zhu, Minshen, Wang, Zifeng, Chen, Zhongfang, Zhi, Chunyi
• Format: Journal Article
• Language: English
• Published: 2016
• Subjects: adsorption; carbon nitride; Catalysts; Doping; durability; Electrocatalysts; electrochemistry; engineering; graphene; Hydrogen evolution; hydrogen production; Oxygen; porous media; Reduction; Stems; Sulfur
• ISSN: 2050-7488; 2050-7496; 2050-7496
• DOI: 10.1039/C6TA03588D

Atomic doping has always been demonstrated as a feasible way to effectively alter the catalytic properties of metal-free electrocatalysts. Herein, we report the first experimental and theoretical investigation regarding the influence of sulfur doping on the activity of a carbon nitride (C 3 N 4 )-based electrocatalyst in the oxygen reduction reaction (ORR) and hydrogen evolution reaction (HER). It is found that the sulfur dopant within the mesoporous carbon-supported C 3 N 4 motif can remarkably boost its ORR activity, which rivals that of commercial Pt/C yet with better cross-over tolerance and durability, while the HER performance of the composite catalyst is superior than most other reported metal-free electrocatalysts and is even comparable to the most active non-noble metal-based HER materials. Theoretical calculations further reveal that the excellent activity of the doped composite stems from the high charge and spin densities in the C 3 N 4 motif as well as altered competent adsorption energies of reaction intermediates via the atomic sulfur doping. The results in this work feature a facile and effective approach for engineering a high performance C 3 N 4 -based electrocatalyst, which may also enlighten the designing and fabrication of other metal-free materials as next-generation electrocatalysts.