Nitrogen-doped carbon dots anchored NiO/Co3O4 ultrathin nanosheets as advanced cathodes for hybrid supercapacitors

Zhenyuan Ji; Kai Liu; Na Li; Hongyan Zhang; Wenyao Dai; Xiaoping Shen; Guoxing Zhu; Lirong Kong; Aihua Yuan

doi:10.1016/j.jcis.2020.06.070

Nitrogen-doped carbon dots anchored NiO/Co₃O₄ ultrathin nanosheets as advanced cathodes for hybrid supercapacitors

J Colloid Interface Sci. 2020 Nov 1:579:282-289. doi: 10.1016/j.jcis.2020.06.070. Epub 2020 Jun 18.

Authors

Zhenyuan Ji¹, Kai Liu², Na Li², Hongyan Zhang², Wenyao Dai², Xiaoping Shen³, Guoxing Zhu², Lirong Kong², Aihua Yuan⁴

Affiliations

¹ School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013, PR China. Electronic address: jizhenyuan@ujs.edu.cn.
² School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013, PR China.
³ School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013, PR China. Electronic address: shenxp@ujs.edu.cn.
⁴ School of Environmental and Chemical Engineering, Jiangsu University of Science and Technology, Zhenjiang 212003, PR China.

PMID: 32593910
DOI: 10.1016/j.jcis.2020.06.070

Abstract

Herein, we demonstrate an advanced cathode of nitrogen-doped carbon dots (NCDs) anchored NiO/Co₃O₄ ultrathin nanosheets for hybrid supercapacitors by a facile hydrothermal-calcination route. Owing to the well defined thin-plate structure and ternary composition, the optimized NiO/Co₃O₄/NCDs nanosheets demonstrate a high specific capacity of 976.3 C g^-1 (1775 F g^-1) at 1 A g^-1, and a splendid cycling stability of approximately 95.7% retention over 10,000 continuous cycles (15 A g^-1). In addition, a hybrid supercapacitor is constructed by using NiO/Co₃O₄/NCDs nanosheets as cathode and reduced graphene oxide (RGO) supported NCDs composites as anode. The obtained NiO/Co₃O₄/NCDs//RGO/NCDs hybrid supercapacitor delivers a maximum energy density of 41.6 Wh kg^-1, together with outstanding cycling stability (no decay after 10,000 cycles at 10 A g^-1). Therefore, the ultrathin sheet-like structured NiO/Co₃O₄/NCDs cathode presents a great potential for supercapacitor application.

Keywords: Carbon dots; Cobalt oxide; Hybrid supercapacitor; Nanosheet; Nickel oxide.