Dual functionalized Fe2O3 nanosheets and Co9S8 nanoflowers with phosphate and nitrogen-doped carbon dots for advanced hybrid supercapacitors

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Switzerland : 1996), 2022-12, Vol.450, p.137942, Article 137942
• Main Authors: Ji, Zhenyuan, Chen, Lizhi, Yu, Hongquan, Dai, Wenyao, Tang, Guanxiang, Li, Huali, Zhu, Guoxing, Yuan, Aihua, Shen, Xiaoping
• Format: Article
• Language: English
• Subjects: Cobalt sulfide; Ferric oxide; Hybrid supercapacitor; Nitrogen-doped carbon dots; Phosphate
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2022.137942

[Display omitted] •Dual functionalized Fe2O3 and Co9S8 with phosphate and NCDs were designed.•The P-Fe2O3/NCDs and P-Co9S8/NCDs electrodes deliver superior properties.•A hybrid supercapacitor was assembled as P-Co9S8/NCDs//P-Fe2O3/NCDs.•The device achieves remarkable energy density and ultrahigh cycling stability. The development of novel electrode materials with admirable electrochemical behaviors is a new opportunity to meet the current demand for the high energy density of supercapacitors. Herein, a facile molecular precursor route is used to synthesize dual functionalized Fe2O3 two-dimensional nanosheets with phosphate and nitrogen-doped carbon dots (P-Fe2O3/NCDs) modifications. Taking full use of the excellent characteristics of each component, the optimized P-Fe2O3/NCDs anode material achieves superior electrochemical features with an outstanding specific capacitance of 453 F g−1 at 1 A g−1. The cycling stability of P-Fe2O3/NCDs nanosheets is as high as 91.0 % after 10,000 cycles at 15 A g−1. Subsequently, phosphate and NCDs modified Co9S8 (P-Co9S8/NCDs) nanoflowers with convenient ion transport properties are fabricated, which possess a satisfied electrochemical capacity of 569 C g−1 at 1 A g−1 with desirable cycling stability at 15 A g−1. Impressively, the designed P-Co9S8/NCDs//P-Fe2O3/NCDs hybrid supercapacitor can achieve an excellent energy density of 85.1 Wh kg−1 at 937.5 W kg−1 and can retain 93.9 % capacitance efficiency after 20,000 cycles at 10 A g−1. The superior properties of the dual functionalized electrode materials provide a new choice for constructing advanced hybrid supercapacitors.