Controlled growth and interaction of NiCo2S4 on conductive substrate for enhanced electrochemical performance

Lee, Hyun Sun; Gund, Girish S.; Park, Ho Seok

doi:10.1016/j.jpowsour.2020.227763

Cited by 29 publications

(18 citation statements)

References 34 publications

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“…Four cycles at each current density from 1 to 32 A/g were performed to calculate capacity retention. Capacity retention of material is percentage measure of its availability to electrolyte ions whose plot is shown in Figure c . The change in capacity retention was found to be 100–44% and 100–64% for K x MnO 2 and Na x MnO 2 thin films, respectively.…”

Section: Resultsmentioning

confidence: 99%

SILAR Grown K⁺ and Na⁺ Ions Preinserted MnO₂ Nanostructures for Supercapacitor Applications: A Comparative Study

Desai

Kulkarni

Gund³

et al. 2021

Energy Fuels

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Herein we have demonstrated facile synthesis approach to grow K + and Na + ions preinserted MnO 2 (K x MnO 2 and Na x MnO 2 ) nanostructured thin films with the help of successive ionic layer adsorption and reaction (SILAR) method. K x MnO 2 and Na x MnO 2 thin films were grown directly on the stainless-steel substrate at room temperature using different reducing agents like manganese sulfate (MnSO 4 ) and sodium borohydride (NaBH 4 ). Reducing agents control reduction of MnO 4− ions, morphological evolution, and preinsertion of Na + ions in MnO 2 matrix. The plausible growth mechanism was proposed behind the occurrence of different morphologies. Due to preinsertion of alkali ions, nonstoichiometric MnO 2 phase was formed and confirmed by X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy studies. The electrochemical measurements of Na x MnO 2 thin films demonstrated and 1.45 times superior specific capacitance at a higher scan rate (100 mV/s) and current density (32 A/g) than those of K x MnO 2 thin films. Enhanced surface capacitance of Na x MnO 2 thin films corresponds to superior electric double layer capacitance (EDLC) and surface redox reactions between Mn 3+ /Mn 4+ ions. On the contrary, K x MnO 2 thin films showed higher diffusion controlled reactions, which were supported by electrochemical impedance spectroscopy (EIS) data. Insertion of Na + ions was found to be advantageous over K + ions, because it provides higher specific capacitance values, specific morphology, improved capacitive retention, accessibility of more electroactive area, stable salt concentration and electrical conductivity of the electrolyte, fast and dynamic utilization of electrode material and higher conservation of energy.

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Section: Resultsmentioning

confidence: 99%

SILAR Grown K⁺ and Na⁺ Ions Preinserted MnO₂ Nanostructures for Supercapacitor Applications: A Comparative Study

Desai

Kulkarni

Gund³

et al. 2021

Energy Fuels

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“…The electrocatalytic activity of this composite film is excellent due to easy ion transportation from Ni(OH) 2 nanosheets to the substrate, large electrochemical surface area, and abundant catalytically active sites. [27][28][29] Therefore, it is necessary to develop facile and scalable approaches to produce Ni(OH) 2 /rGO composite film, which is directly deposited on Ni foam substrate for better electrocatalytic performance. Among the various methods, dip-coating and electrodeposition methods are eco-friendly, low cost as well as compatible for industrial scale.…”

Section: Introductionmentioning

confidence: 99%

“…Whereas, in second route, the rGO nanosheets are directly coated on the substrate followed by Ni(OH) 2 deposition. The electrocatalytic activity of this composite film is excellent due to easy ion transportation from Ni(OH) 2 nanosheets to the substrate, large electrochemical surface area, and abundant catalytically active sites 27‐29 . Therefore, it is necessary to develop facile and scalable approaches to produce Ni(OH) 2 /rGO composite film, which is directly deposited on Ni foam substrate for better electrocatalytic performance.…”

Section: Introductionmentioning

confidence: 99%

Synthesis of nickel hydroxide/reduced graphene oxide composite thin films for water splitting application

et al. 2020

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Facile synthesis of highly efficient and low-cost electrocatalyst for oxygen evolution reaction (OER) is important for large-scale hydrogen production. Herein, nickel hydroxide/reduced graphene oxide (Ni(OH) 2 /rGO) composite thin film was fabricated using dip-coating followed by electrodeposition method on Ni foam substrate at room temperature. The deposited composite film shows amorphous nature with ultra-thin Ni(OH) 2 nanosheets vertically coated on rGO surface, which provides large electrochemical surface area and abundant catalytically active sites. It exhibits a low overpotential of 260 mV @10 mA cm −2 as compared to the pristine electrodes and excellent long-term stability up to 20 hours in 1 M KOH solution. The electrochemical active surface area and Tafel slope of the composite electrode are 20.2 mF cm −2 and 35 mV dec −1 , respectively. The superior water oxidation performance is a result of high catalytically active sites and improved conductivity of the composite electrode.

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“…[17] Moreover, the primary peaks at 856.01 and 857.72 eV with corresponding satellite peaks at 861.35 and 864.06 eV confirmed the presence of inherent Ni 2+ (NiS) and Ni 3+ (NCS, Ni 3 S 4 ) species, respectively, in NCS/NiS-10. [18] The increase in area under the peak corresponding to the Ni 2+ state and peak downshift suggested that the ultrathin shell consisted primarily of NiS phase and sulfurization was successful (Figure 1e). [19] The peak ratio of Ni 2+ (NiS, NCS) and Ni 3+ (surface-oxidized NiOOH, Ni 3 S 4 ) was 2.81, confirming that the primary component of the nanoshell was NiS.…”

Section: Synthesis and Physical Characterization Of The Ncs/nis Elect...mentioning

confidence: 99%

Surface Roughening Strategy for Highly Efficient Bifunctional Electrocatalyst: Combination of Atomic Layer Deposition and Anion Exchange Reaction

et al. 2021

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nontoxic, abundant, and durable catalysts with high activity toward the oxygen and hydrogen evolution reactions (OER and HER, respectively) are preferred. [3] Electrode material and architecture play critical roles in electrocatalytic water splitting. [4] Electrochemical reactions occur at the electrode-electrolyte interface; therefore, electrochemical processes are interfacedependent. Typically, only a fraction of the exposed sites, namely the surface active sites, participates in the electrochemical charge transfer process (Scheme 1a). The electrochemically active surface area (ECSA) generated by the electrical double layer formed at the electrode-electrolyte interface features numerous inactive surface sites that do not participate in electrochemical charge transfer (electronation-deelectronation). Building 3D architectures with large ECSAs is a common method for increasing active surface sites and accelerating electrochemical water splitting (Scheme 1b). In particular, coreshell architectures are highly desirable for good electrode performance because they combine the distinct properties of the core and shell materials used to build multifunctional electrodes. [5] For example, core-shell electrodes with NiCo 2 S 4 (NCS) cores and various shell structures have been evaluated for electrocatalytic water splitting. [6] However, coreshell architectures lengthen the electron transport pathways and increase electrode mass and interfacial resistance, hindering the efficient electrode utilization. The increase in total mass results in lower mass activity, although the estimated electrochemical performance of the core-shell structure is superior to that of the core structure as a function of the geometric area of the electrodes. Hence, developing innovative electrode nano-architectures to increase the N A with higher mass activity is an important task for developing commercial electrochemical energy conversion and storage devices. Nano-roughening the outer surfaces of nanostructures is an advanced method for increasing N A . It has similar ECSAs compared to conventional core-shell structures, but a greater proportion of active sites and massive mass activity. The ECSAs of the structures in Scheme 1b,d are the same; however, the ratio of active to inactive sites of the structure in Scheme 1d is higher than that of the structure in Scheme 1b. This can be achieved using several approaches, such as top-down physical etching, controlled Electrocatalytic water splitting, which is an interface-dominated process, can be significantly accelerated by increasing the number of front-line surface active sites (N A ) of the electrocatalyst. In this study, a unique method is used for increasing the N A by converting the smooth ultrathin atomic-layer-deposited nanoshells of the electrocatalysts into nano-roughened active shell layers using a controlled anion-exchange reaction (AER). The coarse thin nanoshells present abundant surface active sites, which are generated owing to the inherent unit-cell volume mismatch induced during th...

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Controlled growth and interaction of NiCo2S4 on conductive substrate for enhanced electrochemical performance

Cited by 29 publications

References 34 publications

SILAR Grown K⁺ and Na⁺ Ions Preinserted MnO₂ Nanostructures for Supercapacitor Applications: A Comparative Study

SILAR Grown K⁺ and Na⁺ Ions Preinserted MnO₂ Nanostructures for Supercapacitor Applications: A Comparative Study

Synthesis of nickel hydroxide/reduced graphene oxide composite thin films for water splitting application

Surface Roughening Strategy for Highly Efficient Bifunctional Electrocatalyst: Combination of Atomic Layer Deposition and Anion Exchange Reaction

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Controlled growth and interaction of NiCo2S4 on conductive substrate for enhanced electrochemical performance

Cited by 29 publications

References 34 publications

SILAR Grown K+ and Na+ Ions Preinserted MnO2 Nanostructures for Supercapacitor Applications: A Comparative Study

SILAR Grown K+ and Na+ Ions Preinserted MnO2 Nanostructures for Supercapacitor Applications: A Comparative Study

Synthesis of nickel hydroxide/reduced graphene oxide composite thin films for water splitting application

Surface Roughening Strategy for Highly Efficient Bifunctional Electrocatalyst: Combination of Atomic Layer Deposition and Anion Exchange Reaction

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Product

Resources

About

SILAR Grown K⁺ and Na⁺ Ions Preinserted MnO₂ Nanostructures for Supercapacitor Applications: A Comparative Study

SILAR Grown K⁺ and Na⁺ Ions Preinserted MnO₂ Nanostructures for Supercapacitor Applications: A Comparative Study