Co₃S₄ Nanoplate Arrays Decorated with Oxygen-Deficient CeO₂ Nanoparticles for Supercapacitor Applications

Abstract

Cobalt sulfide is favorable for supercapacitors, but its application is inhibited by the inherent slow charge transfer kinetics and poor stability in alkaline solution. Herein, zeolitic imidazole framework (ZIF)-derived Co3S4 nanoplate arrays (NPAs) decorated with CeO2 nanoparticles (NPs) grown on Ni foam have been developed. The obtained Co3S4/CeO2-NPAs display a 2D leaf-like nanoplate morphology (average thickness of nearly 230 nm) with a large amount of oxygen vacancies and exhibits remarkably boosted specific capacity/capacitance, i.e., 1155.8 C/g (2408 F/g) at 0.5 A/g with a notable rate capability (76.5% at 10 A/g), compared to Co3S4-NPAs or CeO2 NPs. More importantly, a two-electrode cell comprising the Co3S4/CeO2-NPAs and an activated carbon electrode displays a high energy density of 45.4 Wh/kg (at a power density of 850 W/kg) with decent long-term durability. Furthermore, a red light-emitting diode can be lighted up for 10 min by two charged cells, showing great prospect of Co3S4/CeO2-NPAs. The outstanding electrochemical properties of the Co3S4/CeO2-NPAs are mainly attributed to the 2D nanoplate morphology with much accessible active sites and the introduction of CeO2 NPs. The Co3S4/CeO2-rich interfaces promote electron transfer between Co3S4 and CeO2. The abundant oxygen vacancies adhere to the surface of Co3S4 and can enhance the electronic conductivity and the capture of OH–. In addition, the CeO2 layer can protect the Co3S4-NPAs from corrosion by the KOH electrolyte during the electrochemical process. Therefore, the electrode developed by this work has great potential in electrochemical applications.

MOF-derived hierarchical core–shell hollow Co3S4@NiCo2O4 nanosheet arrays for asymmetric supercapacitors

“…32 The oxygen defects not only can act as the active sites, but also can act as the ion transport channels, thus increasing the conductivity of the electrode. 34 Fig. 2 shows the FESEM images of the samples at different synthesis stages.…”

“…In addition, as the scanning rate increases, the potential gap between the cathodic and anodic peaks of Co 3 S 4 @NiCo 2 O 4 /rGO/NF extends since a higher potential is required for the faradaic reaction at a large scanning rate. 34 The GCD curves of Co 3 S 4 @NiCo 2 O 4 /rGO/NF at different current densities with a potential window of 0-0.5 V (vs. SCE) are shown in Fig. 4c.…”

Rare Earth‐Based Nanomaterials for Supercapacitors: Preparation, Structure Engineering and Application

“…The hybridization of RE material and TMSs is a powerful solution to elevate the electrochemical properties of corresponding pristine material. Han and co‐workers developed ZIF‐derived Co 3 S 4 nanoplates decorated with CeO 2 nanoparticles obtained by ZIF‐engaged route following by solvothermal method [271] . The hybridization of oxygen vacancies‐rich CeO 2 nanoparticles and Co 3 S 4 introduces vacancies and electric field between the heterojunction interface, which accelerates the charge transfer kinetics.…”

Co2P decorated Co3O4 nanocomposites supported on carbon cloth with enhanced electrochemical performance for asymmetric supercapacitors

“…Among the multifarious TMOs, Co 3 O 4 has been regarded as a battery-type electrode for potential application in SCs owing to its high capacitance, high activity towards the faradaic redox reaction and excellent reversibility. 15,16 Until now, a series of Co 3 O 4 with various types of morphologies, such as nanoparticles, 17 nanowires, 18 nanosheets, 4,19 nanoflowers 20 and nanoboxes, 21 have been successfully synthesized as designed. However, the electrochemical performances of most of the pure Co 3 O 4 nanomaterials are relatively unsatisfactory because of the inherent poor electrical conductivity, leading to slow electron transfer and a low ion adsorption/desorption rate, resulting in low specific capacitance and poor rate performance.…”

“…As is known, according to the electrochemical energy storage mechanisms, the electrode materials based on the reversible faradaic redox reaction process could lead to much greater charge storage (10-100 times) than electrical double-layer capacitors (EDLCs) in which the energy storage relies on the rapid electrostatic charge adhesion on the surfaces of electrodes (non-faradaic processes) such as carbonaceous electrode materials. [4][5][6][7] Generally, faradaic processes can be divided into capacitive and non-capacitive faradaic processes, which correspond to pseudocapacitor and battery-type electrodes respectively. 8,9 Recently, commercialized carbon-based EDLCs have only achieved a relatively inferior energy density (less than 10 W h kg À1 ), which still cannot satisfy the increasing demand for large-scale commercial applications.…”