Surface activated Co3O4/MoO3 nanostructured electrodes by air-plasma treatment toward enhanced supercapacitor

• Published in: Materials science & engineering. B, Solid-state materials for advanced technology Solid-state materials for advanced technology, 2022-11, Vol.285, p.115928, Article 115928
• Main Authors: Chen, Jinyu, Nakate, Umesh T., Nguyen, Que T., Wei, Yuwen, Park, Sungjune
• Format: Article
• Language: English
• Subjects: Air-plasma treatment; Capacitance; Charge transfer; Cobalt oxides; Electrochemical analysis; Electrodes; Metal oxides; Molybdenum trioxide; Nanosheet-like MoO3; Nanostructure; Nanostructured Co3O4; Nyquist plots; Potassium hydroxides; Specific capacitance; Supercapacitor; Surface activation; Synergistic effect
• ISSN: 0921-5107; 1873-4944
• DOI: 10.1016/j.mseb.2022.115928

[Display omitted] •Hydrothermal and annealing for the synthesis of Co3O4/MoO3 nanostructured electrode.•Air-plasma treatment to modify the electrode surface.•Supercapacitor study of Co3O4/MoO3 composite Electrode in 1 M KOH.•The specific capacitance of 141F g−1 at 1 A/g achieved.•Excellent GCD properties of electrode with 1000 cycles stability. Herein, nanostructured Co3O4, MoO3, and Co3O4/MoO3 composite electrodes were prepared via hydrothermal synthesis and investigated for supercapacitive properties. The Co3O4/MoO3 composite electrode with equal weight ratio (named C5M5) showed the highest electrochemical properties compared to other electrodes. Air-plasma treatment further enhanced electrochemical performances owing to synergistic effects and surface activation of the Co3O4/MoO3 composite. The air-plasma surface-activated Co3O4/MoO3 composite (i.e. C5M5-P) electrodes exhibited a specific capacitance of 141F g−1 at 1 A g-1 in 1 M potassium hydroxide electrolyte. The fastest charge transfer and smallest resistance (1.64 Ω) were recorded for optimal electrode as demonstrated by Nyquist plots analysis. The surface-controlled process provided more than 50 % of capacity for the scan rates above 0.2 mV s−1, indicating the efficient pseudocapacitive behavior and showing the outstanding rate capability. The C5M5-P electrode exhibited superior cycling stability with 91.4 % capacitance retention at 3 A g-1 for 1,000 cycles.