Nitrogen-Doped Ketjenblack Carbon Supported Co3O4 Nanoparticles as a Synergistic Electrocatalyst for Oxygen Reduction Reaction.

Gao Cheng,Liya Chen,Lin Yu,Jiaxi Han,Peng Liu,Bang Lan,Guanliang Liu,Wei Song,Fei Ye,Shengbo Han,Ming Sun

doi:10.3389/fchem.2019.00766

Abstract

Developing a highly active and cost-effective cathode electrocatalyst with strong stability for oxygen reduction reaction (ORR) is extremely necessary. In this work, we reported a facile synthetic path to prepare a hybrid nanostructure formed of nitrogen-doped Ketjenblack carbon (N-KC) supported Co3O4 nanoparticles (Co3O4/N-KC), which could be used as a promising and stable electrocatalyst for ORR. Compared with the physical mixture of Co3O4 and N-KC and pure N-KC samples, the resulting Co3O4/N-KC nanohybrid afforded remarkably superb ORR activity with a half-wave potential of 0.82 V (vs. reversible hydrogen electrode, RHE) and a limiting current density of 5.70 mA cm−2 in KOH solution (0.1 M). Surprisingly, the Co3O4/N-KC sample possessed a similar electrocatalytic activity but better durability to the 20 wt% Pt/C catalyst. The remarkable ORR activity of the Co3O4/N-KC nanohybrid was mainly due to the strong coupling effect between Co3O4 and N-KC, the N species dopant, high electroconductivity, and the large BET surface area. Our work enlightens the exploitation of advanced Co3O4/carbon hybrid material alternative to the Pt-based electrocatalysts.

Highlights

With an ever-growing demand in electricity energy supply, electrical energy storage (EES) technology has witnessed booming progress by rapidly exploitative next-generation electrochemical power storage devices, such as supercapacitors (Zhong et al, 2015; Wang S. et al, 2019), Li-ion batteries (Liu et al, 2017; Xia et al, 2017), Zn-ion batteries (Yu et al, 2019), and metal-air batteries (Cheng and Chen, 2012)
We reported a facile synthetic path to prepare a hybrid nanostructure formed of nitrogen-doped Ketjenblack carbon (N-KC) supported Co3O4 nanoparticles (Co3O4/N-KC), which could be used as a promising and stable electrocatalyst for oxygen reduction reaction (ORR)
The efficient energy conversion of zinc-air batteries (ZABs) is still dramatically hindered by the slow oxygen reduction reaction (ORR) kinetics at cathode, which significantly restricts the quality of ZABs (Guo et al, 2018)

Summary

INTRODUCTION

With an ever-growing demand in electricity energy supply, electrical energy storage (EES) technology has witnessed booming progress by rapidly exploitative next-generation electrochemical power storage devices, such as supercapacitors (Zhong et al, 2015; Wang S. et al, 2019), Li-ion batteries (Liu et al, 2017; Xia et al, 2017), Zn-ion batteries (Yu et al, 2019), and metal-air batteries (Cheng and Chen, 2012). Due to the strong coupling effect between Co3O4 and N-KC, the N species dopant, high electroconductivity and large BET surface area, the resultant Co3O4/N-KC nanohybrid exhibited superior ORR catalytic performance than the Co3O4 + NKC and pure N-KC control samples in an alkaline condition. Such a hybrid Co3O4/N-KC electrocatalyst showed a comparable ORR performance (half-wave potential and diffusion-limiting current) to that of Pt/C. Where Id, Ir, and N represent the disk current, the ring current and the collection efficiency of the RRDE, respectively

RESULTS AND DISCUSSION

CONCLUSION

DATA AVAILABILITY STATEMENT