The effect of annealing temperature, reaction time, and cobalt precursor on the structural properties and catalytic performance of CoS2 for hydrogen evolution reaction

Jaberi, Seyedeh Yasaman Shajaripour; Khajehsaeidi, Zahra

doi:10.1016/j.ijhydene.2020.10.224

Cited by 17 publications

(7 citation statements)

References 49 publications

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“…where D is crystallite size, β is full width at half maximum, λ is the wavelength of the X-ray used, and θ is the diffraction angle. 38,39 50Ac50Cl, 20Ac80Cl, and 0Ac100Cl, respectively, as depicted in Figure 2B. The results indicate that the Co−Co 3 O 4 thin film prepared with the molar ratio of 20Ac80Cl has the smallest crystallite size and may offer a high surface area for enhancing redox reactions to increase charge storage.…”

Section: Resultsmentioning

confidence: 90%

“…where D is crystallite size, β is full width at half maximum, λ is the wavelength of the X-ray used, and θ is the diffraction angle. 38,39 21 Furthermore, from the crystallite size analysis of the Co 3 O 4 (400) peak in Figure 2B, it is observed that the addition of cobalt chloride to cobalt acetate causes the crystallite size to decrease from 40.6 nm (100Ac0Cl) to 25.2 nm (20Ac80Cl) as the chloride content increases. This could be a result of the higher ionic radius (181 pm) of the chloride anion (Cl − ) compared to the ionic radius of 121 pm of the acetate anion (CH 3 COO − ), which restricts the growth of the acetate ions during the synthesis process.…”

Section: Resultsmentioning

confidence: 93%

“…The crystallite size analyses of the Co (100), Co (101), and Co 3 O 4 (400) planes for the Co–Co 3 O 4 thin film composites prepared by the different molar ratios of cobalt acetate and cobalt chloride were estimated by Scherrer’s formula in eq . D = 0.94 λ β cos θ where D is crystallite size, β is full width at half maximum, λ is the wavelength of the X-ray used, and θ is the diffraction angle. , The average crystallite size values of Co are 21.3, 22.2, 21.7, 19.2, and 29.9 nm for 100Ac0Cl, 80Ac20Cl, 50Ac50Cl, 20Ac80Cl, and 0Ac100Cl, correspondingly, as shown in Figure B. Also, the crystallite size of Co 3 O 4 is 40.6, 34.2, 36.4, 25.2, and 32.2 nm for 100Ac0Cl, 80Ac20Cl, 50Ac50Cl, 20Ac80Cl, and 0Ac100Cl, respectively, as depicted in Figure B.…”

Section: Resultsmentioning

confidence: 99%

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Effect of Molar Ratio Modulation of Cobalt Precursors on Supercapacitor Behavior of Engineered Co–Co₃O₄ Nanocomposite Electrodes

Nuamah

Noormohammed

Sarkar

2022

ACS Appl. Eng. Mater.

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Nanostructured Co−Co 3 O 4 composite thin films deposited on nickel foam (NF) using combined cyclic voltammetry (CV) and pulse reverse potential (CV PRP) modes of electrodeposition from an electrolyte composed of CoCl 2 and Co(CH 3 COO) 2 precursor salt solutions with varied molar ratios demonstrated a dependency of the supercapacitance performance over the precursor components' molar ratios. The specific capacity and its retention were found to increase with increasing CoCl 2 in the electrolyte with a starting value of 474.6 C/g (791 F/g) at an applied current load of 1 A/g for a molar ratio of Co(CH 3 COO) 2 :CoCl 2 of 100:0. High specific capacity of 1548 C/g (2580 F/g) and large retention (90.5%) were obtained at a critical molar ratio of Co(CH 3 COO) 2 :CoCl 2 of 20:80. However, with 100% CoCl 2 in the electrolyte, the specific capacity lowered to 276 C/g (460 F/g) with poor retention of only 60%. Crystallinity and morphological features, driven by the electrolyte concentration with molar variations of the deposited films, have been found to influence the specific capacitance performance. The degree of crystallinity, and the presence of Co and Co 3 O 4 phases for the different molar ratios have been revealed by X-ray diffraction (XRD) studies. The diverse morphological features obtained by scanning electron microscopy (SEM) and the varying quantities of Co and O in the Co−Co 3 O 4 nanocomposite thin films as confirmed by energy-dispersive X-ray spectroscopy (EDX) spectra correlate well with the electrochemical performance. The phase composition was further confirmed by the presence of Co−O bonds via the attenuated total reflection−Fourier transform infrared (ATR-FTIR) spectra obtained on these films.

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Section: Resultsmentioning

confidence: 90%

Section: Resultsmentioning

confidence: 93%

Section: Resultsmentioning

confidence: 99%

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Effect of Molar Ratio Modulation of Cobalt Precursors on Supercapacitor Behavior of Engineered Co–Co₃O₄ Nanocomposite Electrodes

Nuamah

Noormohammed

Sarkar

2022

ACS Appl. Eng. Mater.

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“…After the sulfurization process, the intensity for Co 2+/3+ in both sites is weakened with the Co/ Fe−S bond formation, as indicated by the arisen peak located at 1126 cm −1 . 43 The SEM images of the above samples at different stages are shown in Figures S2 and S3…”

Section: Resultsmentioning

confidence: 99%

“…The peaks at 3425 and 1634 cm –1 can be assigned to the stretching vibration of O–H in free water and the O–H vibrations of the absorbed water, respectively. After the sulfurization process, the intensity for Co 2+/3+ in both sites is weakened with the Co/Fe–S bond formation, as indicated by the arisen peak located at 1126 cm –1 …”

Section: Results and Discussionmentioning

confidence: 99%

Enhancing Co–O Covalency by Low Electronegativity Anion-Induced Charge Rebalance in a (Co,Fe)S₂/Co₃O₄ Composite for Efficient Oxygen Evolution Reaction

Jiang,

Li,

Zhang

et al. 2023

ACS Sustainable Chem. Eng.

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The metal−oxygen covalency is the most advanced descriptor to understanding the relationship between the electronic structure and oxygen evolution reaction (OER) properties of oxide catalysts; however, its regulation strategy by an anion is very limited. Herein, we demonstrated that the Co−O covalency can be enlarged by introducing a second phase of disulfide (Co,Fe)S 2 coupled on the spinel Co 3 O 4 . The S and O with different electronegativity coordinated simultaneously with transition metal ions at the composite interface of (Co,Fe)S 2 /Co 3 O 4 , which brings the oxygen charge shifting toward the metal ions. The strengthened covalency and the charge rebalance between oxygen and metal ions are observed directly by X-ray photoelectron spectroscopy and X-ray absorption spectroscopy, which are further confirmed by the calculated O 2p band center upshift to the Fermi level based on the density functional theory. The reinforced Co−O covalency resulted in an OER overpotential reduction of more than 100 mV compared to the pristine one. This work provides a rational way to enhance the metal−oxygen covalency by constructing a composite phase for elevating the intrinsic OER activity of the catalyst, which may be extendable to other oxides.

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2D Transition Metal Dichalcogenides‐Based Electrocatalysts for Hydrogen Evolution Reaction

Mondal

Vomiero

2022

Adv Funct Materials

133

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Hydrogen is an efficient, clean, and economical energy source, owing to its huge energy density. Electrochemical water splitting is a potential candidate for inexpensive and eco-friendly hydrogen production. Recently, the development of 2D transition metal chalcogenides (TMDs) nanomaterials with a variety of physicochemical properties has shown their potential as eminent non-noble metal-based nanoscale electrocatalysts for hydrogen evolution. Nanostructuring such materials induces deep modification of their functionalities, compared to their bulk counterparts. High density of different types of exposed active sites is formed, and the small diffusion paths, which enhances the electron transfer in the 2D structures, can successfully aid the charge collection process in the electrocatalytic hydrogen evolution reactions. In this review, the key parameters to improve the catalyst performance of 2D TMDs in electrochemical hydrogen evolution reaction (HER) processes are discussed in detail and the most recent developments in the field are summarized, focusing on the improvement of the electrocatalytic activity of 2D TMDs. This review delivers deep insight for the clear understanding of the potential of 2D TMDs nanoscale materials as electrocatalysts for HER, suggesting the development of new type of catalyst with efficient activity in HER as well as other renewable energy fields.

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The effect of annealing temperature, reaction time, and cobalt precursor on the structural properties and catalytic performance of CoS2 for hydrogen evolution reaction

Cited by 17 publications

References 49 publications

Effect of Molar Ratio Modulation of Cobalt Precursors on Supercapacitor Behavior of Engineered Co–Co₃O₄ Nanocomposite Electrodes

Effect of Molar Ratio Modulation of Cobalt Precursors on Supercapacitor Behavior of Engineered Co–Co₃O₄ Nanocomposite Electrodes

Enhancing Co–O Covalency by Low Electronegativity Anion-Induced Charge Rebalance in a (Co,Fe)S₂/Co₃O₄ Composite for Efficient Oxygen Evolution Reaction

2D Transition Metal Dichalcogenides‐Based Electrocatalysts for Hydrogen Evolution Reaction

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The effect of annealing temperature, reaction time, and cobalt precursor on the structural properties and catalytic performance of CoS2 for hydrogen evolution reaction

Cited by 17 publications

References 49 publications

Effect of Molar Ratio Modulation of Cobalt Precursors on Supercapacitor Behavior of Engineered Co–Co3O4 Nanocomposite Electrodes

Effect of Molar Ratio Modulation of Cobalt Precursors on Supercapacitor Behavior of Engineered Co–Co3O4 Nanocomposite Electrodes

Enhancing Co–O Covalency by Low Electronegativity Anion-Induced Charge Rebalance in a (Co,Fe)S2/Co3O4 Composite for Efficient Oxygen Evolution Reaction

2D Transition Metal Dichalcogenides‐Based Electrocatalysts for Hydrogen Evolution Reaction

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Product

Resources

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Effect of Molar Ratio Modulation of Cobalt Precursors on Supercapacitor Behavior of Engineered Co–Co₃O₄ Nanocomposite Electrodes

Effect of Molar Ratio Modulation of Cobalt Precursors on Supercapacitor Behavior of Engineered Co–Co₃O₄ Nanocomposite Electrodes

Enhancing Co–O Covalency by Low Electronegativity Anion-Induced Charge Rebalance in a (Co,Fe)S₂/Co₃O₄ Composite for Efficient Oxygen Evolution Reaction