Highly dispersed Co4N nanoparticles coated by g-C3N4 nanotube: An active bifunctional electrocatalyst for oxygen reduction and oxygen evolution reaction

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Switzerland : 1996), 2021-06, Vol.413, p.127954, Article 127954
• Main Authors: Wang, Nannan, Hao, Bonan, Chen, Hao, Zheng, Rongkang, Chen, Baojie, Kuang, Shihong, Chen, Xiaodong, Cui, Lifeng
• Format: Article
• Language: English
• Subjects: Bifunctional electrocatalyst; Co4N nanoparticle; g-C3N4 nanotube; Oxygen evolution reaction; Oxygen reduction reaction
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2020.127954

The Co4N nanoparticles coated by 1D conductive g-C3N4 nanotube was synthesized by an in-situ and facile process. The bifunctional electrocatalyst shows excellent OER and ORR electrochemical activity superior to that of the referenced catalyst. [Display omitted] •Highly dispersed Co4N nanoparticles coated by g-C3N4 nanotube are prepared by an in-situ and facile method.•The active sites Co4N nanoparticles evenly distribute inside of the both ends of g-C3N4 nanotube.•The structure evolution mechanism of g-C3N4 nanotube is investigated.•The Co4N@CNNT catalyst shows excellent ORR and OER catalytic activities. Developing a cost-effective, efficient, and facile prepared electrocatalyst for oxygen reduction (ORR) and evolution reaction (OER) is critical for a range of renewable energy technologies. Herein, we report unique Co4N nanoparticles loading on g-C3N4 nanotubes (Co4N@CNNT) bifunctional electrocatalyst for OER and ORR by an in-situ method. Highly dispersed Co4N nanoparticles as the active sites gather at the top of the g-C3N4 nanotube (CNNT), while the six-fold cavities from smooth CNNT with an outer diameter of 48 nm and an inner diameter of 22 nm act as anchor sites to preferentially coordinate with the active sites. Benefiting from the distinctive structure features, the intrinsic metallic Co4N@CNNT exhibits high electrocatalytic performances. Electrochemistry studies show that an onset potential of 0.94 V and a half-wave potential of 0.86 V of Co4N@CNNT are obtained that are superior to Pt/C catalyst. A low overpotential of 285 mV at an anodic current density of 10 mA cm−2 during the OER process is obtained that is superior to the IrO2 catalyst; and lower Tafel plot and good durability are also observed. Our findings provide a new strategy for the fabrication of an efficient bifunctional electrocatalyst for OER and ORR.