The evaluation of the electrochemical properties of Co3O4 nanopowders synthesized by autocombustion and sol-gel methods

doi:10.21203/rs.3.rs-3022698/v1

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The evaluation of the electrochemical properties of Co3O4 nanopowders synthesized by autocombustion and sol-gel methods

https://doi.org/10.21203/rs.3.rs-3022698/v1

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published 02 Oct, 2023

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In present work, we investigated the synthesis methods for producing spherical-shaped nanomaterials of spinel cobalt oxide (Co₃O₄) as electrode materials. Two synthesis methods, autocombustion (Co₃O₄-AC) and sol-gel (Co₃O₄-SG), were employed to synthesize cobalt oxide nanopowders with a spherical shape. Characterization techniques including XRD, TEM, BET, and XPS analyses were conducted to evaluate the synthesized samples. The phase purity of the cobalt oxide samples were probed using XRD analysis and the crystallite size was determined to be 44 nm for Co₃O₄-AC and 36 nm for Co₃O₄-SG. TEM analysis further confirmed the desired spherical morphology of the particles. The surface area of Co₃O₄-AC was found to be 15 m²/g, while Co₃O₄-SG exhibited a slightly lower surface area of 11 m²/g. The energy storage experiments were conducted in terms of CV and GCD to enhance the electrochemical performance of the samples. Co₃O₄-AC exhibited a higher Cs 162 F/g at Im (current density) 0.25 A/g, indicating its superior energy storage capability. On the other hand, Co₃O₄-SG shows a Cs 98 F/g, indicating slightly lower execution compared to Co₃O₄-AC. Both nanomaterials exhibited excellent stability, showing no degradation over 1000 charge-discharge cycles. Overall, the study successfully synthesized spherical-shaped cobalt oxide nanomaterials using autocombustion and sol-gel methods. The obtained results demonstrate the promising energy storage properties of Co₃O₄-AC and Co₃O₄-SG, with Co₃O₄-AC exhibiting higher specific capacitance.

Co3O4

autocombustion

sol-gel

GCD

cycle stability

Growing world as well as population leads to scarcity of jobs, basic needs that increases industrialization rapidly to overcome these scarcities. Even natural energies are limited to use for our daily needs like lightening, batteries and etc. so concerning these points researchers are more interest among to improve the nanomaterials which gives better solution for our daily needs i.e., energy sources that we can use rather than the natural sources. (Berenguer et al. 2016; Khaldakar et al. 2017; Pinky et al. 2015). The physical properties and versatility of complex transition metal oxides have sparked significant research interest, particularly their ability to easily interact with other materials. Among these oxides, cobalt oxide is of particular interest due to its stable spinel structure and p-type semiconducting properties. This is attributed to the presence of both Co²⁺ (high-spin divalent) and Co³⁺ (low-spin trivalent) ions, which occupy tetrahedral and octahedral sites, respectively. These characteristics make cobalt oxide suitable for an extensive applications, such as catalytic, optics, magnetism, and gas sensing (Reena et al., 2020; Shaheen et al., 2020). In contemporary days, Co₃O₄ nanomaterials gains more attentiveness in research, by virtue of its eco-friendly nature, corrosion and oxidation resistance, high surface area, and chemical stability (Warsi et al., 2021). The spinel structure of Co₃O₄ nanomaterials is particularly appealing due to their magnetic and electronic properties, as well as their enhanced surface reduction-oxidation behaviour. These characteristics enable a variety of applications, including energy storage in batteries, energy conversion, and magnetic devices with resistance, and gas sensors. The specific atomic-level arrangement of the material's surface plays a crucial role in determining its properties and performance in these applications (Ribeiro et al., 2018). Authors prepared Co₃O₄ metal oxide nanomaterials via co-precipitataion method which shows pseudocapacitance nature are greater attention towards energy conversion and storage applications as a supercapacitor, Li-ion batteries (Vijayanand et al. 2013; Ramsundar et al. 2015). Growing such high-performance nanomaterials for the energy storage characteristics are key towards electrochemical applications.

In a study conducted by Ullah et al. (2020), the effect of different concentrations of precipitants, namely NaOH and NH4OH, on the morphological, structural, and magnetic properties of Co3O4 nanomaterials was investigated. The authors used a 1:3 ratio of precursor (Co(NO₃)2·6H₂O) to precipitating agents (NaOH and NH₄OH) for the synthesis of Co₃O₄ via a low-temperature precipitation method. The variation in precipitants and their concentrations played a significant role in determining the surface morphology of Co₃O₄, as confirmed by FESEM analysis. These variations also enhanced the material's activity for various applications. In another study, Uma Sudharshini et al. (2020) synthesized Co₃O₄ cubic spinel structures with sheet-like morphologies using a solvothermal method at a low-temperature reaction process. The resulting material exhibited a lower ferromagnetic nature but had a high Cs (specific capacitance) of 778 F/g. These characteristics succeed to an effective electrode material for supercapacitors, attributed to its high surface-volume ratio and shorter path length. Li et al. (2021) focused on the requirements for cost-effective catalysts with high oxygen evolution reaction (OER) activity in zinc-air batteries. To address this, they prepared a zinc-air battery using a poly-active centric Co₃O₄-CeO₂/Co-N-C composite with a higher surface area through a facile process. The composite demonstrated a C_s of 728 mA h/g at 20 mA/cm² and exhibited longer stability, thanks to the synergistic effects of the components present in the composite. Nickel foam, copper foam, Nickel mesh and stainless steel (SLS) mesh as electrocatalysts for oxygen evolution and water splitting in alkaline media. Among these nickel foam & SLS substrate shows good results towards oxygen evolution & water splitting applications. The Nickel foam and SLS electrode shows stable for electrocatalytic applications (Hu et al. 2019). Carbon nanomaterial using Acacia auriculiformis pods for energy storage measurement as supercapacitors are prepared to conduct Electrochemical experiments and coated on surface of Nickel foam substrate, shows high performance towards supercapacitors (Bhat et al. 2021). In a study by Zallouz et al. (2021), Co₃O₄ nanomaterials embedded in mesoporous carbon and subjected to pyrolysis exhibited a specific capacitance of 54 F/g at a current density of 1.0 A/g. The material also demonstrated 82% stability over 10,000 cycles. Another research conducted by Liao et al. (2015) involved the synthesis of a Co₃O₄/vertically aligned graphene nanosheets (VAGN)/carbon fabric hybrid composite through a hydrothermal method. This composite displayed a capacitance of 580 F/g and retention stability of 86.3% over 20,000 cycles, at a high Im of 20 A/g. Additionally, it showed an E.D. (energy density) of 80 Wh/kg and a P.D. (power density) of 20 kW/kg. Li et al. (2016) synthesized Co₃O₄ using a solution process at 70°C, resulting in a specific capacitance of approximately 304 F/g (Cs) with a 1 M KOH electrolyte solution. However, when Co3O4 was combined with super-P-carbon to form a pseudo-supercapacitor, the Cs value increased to around 480 F/g. This Co₃O₄-based nanomaterial demonstrated excellent retention stability of approximately 88.6% over 1000 cycles. In this study, we focused on synthesizing cobalt oxide nanomaterials with a spherical morphology using various synthesis methods. The synthesized nanomaterials were then characterized to determine their purity and morphology. The Cs of the nanomaterials was measured to be 162 F/g for Co₃O₄-AC and 98 F/g for Co₃O₄-SG at Im of 0.25 A/g. Furthermore, the prepared nanomaterials exhibited excellent stability, with approximately 100% retention of their performance over 1000 cycles.

2.1 Synthesis of Co₃O₄ via autocombustion and sol-gel methods

To synthesize Co ₃ O ₄ -AC, a mixture containing the appropriate amount of (cobalt nitrate) Co(NO₃)₂·6H₂O as the predecessor and (glycine) NH₂CH₂COOH as a fuel was dissolved in a small quantity of distilled water (dis.H₂O) in a 100 ml crystallizing dish. The reaction mixture was then placed on a preheated hot plate and periodically shaken by hand. As the solution dehydrated, it caught fire, spreading throughout the mass and releasing brown-coloured fumes. Eventually, black-coloured cobalt oxide nanomaterials were formed. The obtained nanomaterials were collected in a silica crucible and calcined at 450°C for approximately 3 hours. Then it is allowed to cool to room temperature, collected in a mortar to crush, finally to obtain fine Co₃O₄-AC (Salunkhe et al., 2012).

To synthesize Co ₃ O ₄ -SG, First, a calculated amount of tartaric acid solution (1.0344 g of tartaric acid in 30 ml of dis.H₂O) and a magnetic bead were taken in a 100 ml crystallizing dish. The dish was then placed on a preheated hot plate set at 50°C for approximately 30 minutes while continuously stirring the mixture. Next, a prepared solution of cobalt nitrate (2 g of cobalt nitrate in 20 ml of dis.H₂O) was added to the tartaric acid solution while stirring continuously. Then temperature of reaction mixture increased to 70°C and maintained at this temperature for 30 minutes. At 70°C, a calculated amount of ethylene glycol (0.4 ml) was added drop-wise to the reaction mixture while continuously stirring. This resulted in the formation of a gel with a light pink color, accompanied by the evolution of brown-coloured gas. The obtained gel was instantly move in to a preheated oven, dried at 70°C for ½ hr. Subsequently, the gel was further dried overnight at 80°C. After drying, the gel was allowed to cool to room temperature and then crushed in a mortar. The crushed gel was collected in a silica crucible and placed in a furnace for calcination at 500°C for 2 hours. During the calcination process, the pink-coloured gel transformed into black-coloured nanomaterial. Once cooled to room temperature, the nanomaterial was collected, ground to obtain the desired fine Co₃O₄-SG (Jagtap et al., 2017).

2.2 Characterization

The synthesized Cobalt oxide (Co₃O₄) nanomaterials obtained through Autocombustion (Co₃O₄-AC) and Sol-gel (Co₃O₄-SG) methods were subjected to characterization using various analytical techniques. The phase purity and morphology of the nanomaterials after calcination were examined using X-ray diffraction (XRD) analysis performed on a PANalytical X'pert Pro diffractometer. Transmission electron microscopy (TEM) analysis was conducted using a FEI Tecnai G2 F30 instrument to further investigate the morphology of the samples. To determine the surface area, pore size, and diameter of the prepared samples, a BET (Brunauer-Emmett-Teller) analysis was carried out using a Belsorp-mini II instrument from Bel, Japan. X-ray photoelectron spectroscopy (XPS) data of Co₃O₄-AC and Co₃O₄-SG were collected using a Thermo K-Alpha X-ray photoelectron spectrometer to gain insight into the chemical composition and electronic states of the nanomaterials. For electrochemical performance evaluation, a three-electrode system was employed. The working electrode was fabricated using the Co₃O₄-AC and Co₃O₄-SG nanomaterials, a saturated Hg/Hg₂Cl₂ electrode served as the reference electrode, and a Pt rod acted as the auxiliary electrode. The electrochemical performance was investigated in 1M KOH electrolyte. Cyclic voltammetry (CV) and galvanostatic charge-discharge (GCD) experiments were conducted using a multichannel potentiostat/galvanostat (AUTOLAB M204) to assess the electrochemical behavior of the synthesized nanomaterials.

Specific capacitance (Cs) using GCD curves, E.D. and P.D. of the samples are calculated using the formulae (Sriram et al. 2021; Alem et al. 2023):

$${\text{C}}_{s}=\text{I}\text{m}\text{*}\frac{{\Delta }\text{t}}{{\Delta }\text{V}}\dots ..\left(1\right)$$

Where, Im is the current density, ΔV is the potential window, ${\Delta }\text{t}$ is discharge time.

$$E.D.= \frac{1}{2}{C}_{s}{\left(\varDelta V\right)}^{2}\dots \dots \left(2\right)$$

$$P.D.= \frac{E.D.}{\varDelta t}\dots \dots .\left(3\right)$$

2.3 Fabrication of working electrode (CV & GCD experiments)

To prepare the working electrode, a homogeneous paste was created by combining 80% of the prepared nanomaterials (Co₃O₄-AC and Co₃O₄-SG), 10% ketjen black, and 10% (PVDF) polyvinylidene fluoride in (NMP) N-methyl-2-pyrrolidone as a solvent. The paste was then coated onto both sides of a pre-cleaned nickel foam substrate measuring 1 cm². The coated electrode was dried at 80°C for approximately 12 hours to ensure complete evaporation of the solvent. To further enhance the electrode's integrity and compactness, a pressure of 100 Kg/cm² was applied by pressing the coated electrode. This process resulted in the formation of the working electrode for further experimentation and analysis.

3.1 TEM (Transmission Electron Microscopy) Analysis

Figure 1 depicts the results obtained from TEM analysis of Co₃O₄-AC and Co₃O₄-SG samples. TEM images (a, d) show the majority of particles exhibiting a spherical morphology, although a few particles appear to have a hexagonal shape. High-resolution TEM images (b, e) provide detailed views of the crystal planes that are exposed. Particle size analysis was performed using Gatan digital micrograph software, and the obtained data was used to generate particle size distribution histograms (Fig. 1(c, f)). The histograms reveal the distribution of particle sizes within each sample. The average particle size was found to be 28 nm for Co₃O₄-AC and 23 nm for Co₃O₄-SG. Furthermore, the interplanar distance (d) between crystal planes was measured and found to be 0.243 nm for Co₃O₄-AC and 0.269 nm for Co₃O₄-SG, specifically corresponding to the (311) crystal planes.

3.2 XRD (X-Ray Diffraction) Analysis

Figure 2 presents powder XRD patterns obtained for the nanomaterials (NM) prepared by Autocombustion (AC) and Sol-gel (SG) methods. In Fig. 2a, the XRD patterns for Co₃O₄-AC and Co₃O₄-SG are displayed, while Fig. 2b shows an enlarged view of the maximum intense peak (311). The XRD patterns of Co₃O₄-AC and Co₃O₄-SG samples closely match the simulated pattern of Co₃O₄ generated from PCW software. This agreement confirms the phase purity of the prepared nanomaterials, as no impurity peaks are observed. Furthermore, the broad peaks observed in the experimental patterns indicate that the crystallites are nano-sized. The crystallite size was calculated using the Debye-Scherrer formula and found to be 44 nm for Co₃O₄-AC and 36 nm for Co₃O₄-SG. The interplanar distance (d) for (311) plane was calculated using Bragg's law (nλ = 2dsinθ) and determined to be 0.2433 nm for Co₃O₄-AC and 0.2432 nm for Co₃O₄-SG. These values are comparable with the interplanar distances observed in the TEM analysis. The lattice parameter (a) was calculated by relating the (hkl) plane to the interplanar distance (d) and found to be 0.8066 nm for both nanomaterials (Chen et al., 2017; Rani et al., 2017).

3.3 BET (Brunauer–Emmett–Teller)) Analysis

Figure 3 presents the N₂ adsorption-desorption isotherms for Co₃O₄-AC (Fig. 3a) and Co₃O₄-SG (Fig. 3b). Prior to the analysis, the samples were subjected to a heating process at 120°C for 3 hours to eliminate any moisture or adsorbed gases. The presence of hysteresis loops in the adsorption-desorption isotherms indicates that the prepared samples possess a mesoporous structure. These samples follow a type-IV adsorption/desorption isotherm pattern. The surface area, pore volume, and pore diameter of Co₃O₄-AC were determined to be 15 m²/g, 0.083 cm3/g, and 22 nm, respectively. In comparison, Co₃O₄-SG exhibited higher values for surface area, pore volume, and pore diameter, measuring 11 m²/g, 0.20 cm³/g, and 73 nm, respectively. This indicates that Co₃O₄-AC has a greater surface area and larger pores compared to Co₃O₄-SG It is important to note that different synthesis methods can lead to variations in surface morphology, thereby affecting the surface area and pore characteristics of the samples.

3.4 X-ray Photoelectron Spectroscopy (XPS) analysis

Figure 4 displays survey spectra of XPS for two nanomaterials, Co₃O₄-AC and Co₃O₄-SG, confirming the presence of peaks corresponding to Cobalt (Co) and oxygen (O). The binding energies of high-resolution XPS spectra of Co2p and O1s were corrected using a reference carbon binding energy of 284.6 eV and then deconvoluted. The deconvoluted outcomes are presented in Fig. 5. The emission spectra of Co2p exhibit two-orbit doublets observed at approximately 779.73 eV and 794.68 eV for both samples, representing 2p_3/2 and 2p_1/2, respectively (Fig. 5a). These values indicate the presence of Co³⁺ at octahedral and Co²⁺ at tetrahedral sites within the samples' sublattice. The binding energies (B.E) of both samples, found after deconvolution, are displayed in Table 1, agree well with previous studies (Jang et al., 2017; Zhang et al., 2021). Figure 5b illustrates the deconvoluted high-resolution O1s spectra for both samples, revealing three components: lattice oxygen (O_L), oxygen vacancies (O_V), and chemically adsorbed oxygen (O_C). The primary peak is situated around 529.61 eV and it is accompanied by broadened shoulders at higher B.E. The binding energies of O_L, O_V, and O_C are approximately 529.6, 531.1, and 532.5 eV, respectively. The O1s B.E values for both samples, as shown in Table 2, align well with existing literature (Eismont et al., 2023; Saddeler et al., 2020). This analysis confirms the presence of metal-oxygen (M-O) bonds, specifically Co-O bonding, in both samples.

Table 1

List of Co2p binding energies of the samples.
Sample	2p_3/2		2p_1/2
Sample	Co³⁺ (eV)	Co²⁺ (eV)	Co³⁺ (eV)	Co²⁺ (eV)
Co₃O₄-AC	779.73	781.52	794.68	796.52
Co₃O₄-SG	779.67	781.57	794.64	796.44

Table 2

List of O1s binding energies of samples.
Sample	O_L (eV)	O_D (eV)	O_C (eV)
Co₃O₄-AC	529.61	531.16	532.56
Co₃O₄-SG	529.55	530.89	532.20

3.5 Cyclic Voltammetry (CV)

The CV experiments conducted for Co₃O₄-AC and Co₃O₄-SG nanomaterials involved varying scan rates such as 5, 10, 25, 50, 75 and 100 mV/s in a three-electrode system using a 1 M KOH electrolyte solution. The obtained CV graphs, shown in Fig. 6, covered a potential window of 0-0.6 V. Both nanomaterials exhibited redox behavior characterized by the presence of anodic and cathodic peaks, indicating their pseudo-capacitive nature. The first pair of redox peaks (A₁/C₁) can be attributed to the faradaic conversion from Co²⁺ in Co₃O₄ to Co³⁺ (CoOOH), as represented by the equation mentioned previously (Pal et al., 2018; Fan et al., 2019).:

Co₃O₄ + OH⁻ + H₂O ↔ 3CoOOH + e- ………. (1)

The second pair of redox peaks (A₂/C₂) observed in the CV curves corresponds to the Faradaic conversion between Co³⁺ (CoOOH) and Co⁴⁺ (CoO₂), as described by the following equation (Liu et al., 2017):

CoOOH + OH⁻ ↔ CoO₂ + H₂O + e- ……. (2)

In the case of the Co₃O₄-AC sample, the migration of peaks observed at higher scan rates can be attributed to the influence of polarization effects and the corresponding increase in internal resistance. These factors contribute to the shifting of the peaks within the cyclic voltammogram. In contrast, the Co₃O₄-SG sample shows the presence of both redox peaks, and the resulting cyclic voltammograms display a nearly rectangular shape, indicating different electrochemical behavior compared to Co₃O₄-AC (Li et al., 2020).

3.6 Galvanostatic charge-discharge (GCD)

The GCD curves obtained at various current densities such as 0.25, 0.5, 0.75, 1.0, 2.5 and 5.0 A/g for Co₃O₄-AC and Co₃O₄-SG are depicted in Figs. 7a and 7b, respectively. Both samples exhibit two distinct plateaus on the discharging curves, indicating the involvement of redox coupling reactions that were observed in the CV analysis. This behaviour signifies the pseudo-capacitive nature of the materials. Comparing the GCD curves at Im of 0.5 A/g (Fig. 7c), it is evident that the Co₃O₄-AC sample displays broader GCD curves compared to the Co₃O₄-SG sample, indicating more charge storage capabilities. This observation is notable considering that Co₃O₄-AC has higher surface area, pore volume, and pore diameter, as determined in the BET analysis. At a lower Im of 0.25 A/g, the specific capacitance (Cs) values for Co₃O₄-AC and Co₃O₄-SG are measured to be 162 F/g and 98 F/g, respectively. However, as the current density increases, the specific capacitance for both materials decreases, as illustrated in Fig. 7d. At all Im, the Cs of Co₃O₄-AC is considerably higher than that of the Co₃O₄-SG. This decrease can primarily be attributed to the limited interaction between the electrolyte and the active material present on the electrode surface.

E.D. and P.D. of Co₃O₄-AC and Co₃O₄-SG nanomaterials was calculated and results obtained were tabulated seen in Table 3 at different current density. The E.D. decreases and the P.D. increases with the increase in current density from 0.25 A/g to 5.0 A/g. Comparatively, Co₃O₄-AC shows relatively higher E.D. than the Co₃O₄-SG nanomaterial.

Table 3

Energy density (E.D) and power density (P.D) values of Co₃O₄- AC and Co₃O₄-SG samples, obtained at different current densities.
Current density Im (A/g)	Co₃O₄ - AC		Co₃O₄-SG
Current density Im (A/g)	E.D (Wh/kg)	P.D (kW/kg)	E.D (Wh/kg)	P.D (kW/kg)
0.25	14.29	0.05	9.92	0.06
0.5	11.91	0.11	8.71	0.11
0.75	11.03	0.16	8.30	0.17
1.0	10.58	0.20	7.39	0.22
2.5	7.03	0.54	5.71	0.57
5.0	6.47	1.08	5.71	1.14

3.7 Electrochemical Impedance Spectra (EIS)

Figure 8 illustrates the EIS spectra or Nyquist plots obtained for the fabricated Co₃O₄-AC and Co₃O₄-SG nanomaterial electrodes. The EIS spectra exhibit distinct characteristics for both electrode materials. In the higher frequency region, a smaller semicircle is observed for the Co₃O₄-AC sample, while a larger semicircle is observed for the Co₃O₄-SG sample. This difference in semicircle size suggests that the Co₃O₄-AC electrode has better charge transport properties at the electrode-electrolyte interface compared to the Co₃O₄-SG electrode. The point of intersection at the x-axis at the highest applied frequency corresponds to the R_S (Ω) or equivalent series resistance (ESR), which represents the total internal resistance of the cell. The R_S values were found to be 1.42 Ω and 1.16 Ω for the Co₃O₄-AC and Co₃O₄-SG electrodes, respectively. The charge transport resistance (R_ct) of the electrode materials can be estimated from the radius of the semicircle, which was determined to be 0.92 Ω for Co₃O₄-AC and 2.06 Ω for Co₃O₄-SG. The presence of a vertical line in the low frequency regions indicates the occurrence of ionic diffusion from the bulk of the solution towards the electrode surface. A more vertical straight line suggests lower diffusive resistance of OH⁻ ions. The Co₃O₄-AC electrode exhibits a more vertical line in the inset of Fig. 8, indicating lower diffusive resistance of OH⁻ ions from the solution towards the electrode surface. This behavior is consistent with studies conducted by Gaire et al. (2020), Ndambakuwa et al. (2021), Hong et al. (2019), Nieto et al. (2021), Ye et al. (2021), and Kharade et al. (2018).

3.8 Stability cycles

The cycle stability of the electrode materials were probed from the charge-dischargecurves recorded up to 1000 cycles under a current density of 5 A/g, and the results are shown in Fig. 9. Both electrode show almost same capacitance retention up to 1000 cycles of experiments. A similar feature of high degree of capacitance retention has been reported for various spinel-structure cobalt oxide systsems (Sharma et al. 2020; Ghosh et al. 2016; Thorat et al. 2017).

The successful synthesis of spherical cobalt oxide nanomaterials using autocombustion and sol-gel methods has been achieved. X-ray diffraction (XRD) analysis confirms the high phase purity of the nanomaterials, with Co₃O₄-AC having a crystallite size of 44 nm and Co₃O₄-SG with a size of 36 nm. Transmission electron microscopy (TEM) analysis further validates the spherical morphology of the nanomaterials. BET analysis reveals that both Co₃O₄-AC and Co₃O₄-SG exhibit mesoporous characteristics, as evidenced by hysteresis loops in N₂ adsorption-desorption isotherms. The surface area, pore volume, and pore diameter of Co₃O₄-AC are determined to be 15 m²/g, 0.083 cm³/g, and 22 nm, respectively, while Co₃O₄-SG exhibits values of 11 m²/g, 0.20 cm³/g, and 73 nm, respectively. Electrochemical characterization through CV and GCD experiments demonstrates the promising energy storage capabilities of both nanomaterials. Co₃O₄-AC achieves a Cs of 162 F/g, while Co₃O₄-SG exhibits 98 F/g at a current density of 0.25 A/g. Furthermore, both nanomaterials exhibit excellent stability, retaining approximately 100% of their capacitance over 1000 cycles. These findings highlight the potential of Co₃O₄-AC and Co₃O₄-SG nanomaterials for energy storage applications, encouraging further investigations and potential practical implementations.

Conflict of interest

On behalf of all authors, the corresponding author states that there is no conflict of interest.

Alem AF, Worku AK, Ayele DW et al (2023) Ag doped Co₃O₄ nanoparticles for high-performance supercapacitor application. Heliyon 9:e13286. https://doi.org/10.1016/j.heliyon.2023.e13286
Berenguer R, Sieben JM, Quijada C et al (2016) Electrocatalytic degradation of phenol on Pt- and Ru-doped Ti/SnO₂-Sb anodes in an alkaline medium. Appl Catal B 199:394–404. https://doi.org/10.1016/j.apcatb.2016.06.038
Bhat VS, Jayeoye TJ, Rujiralai T et al (2021) Acacia auriculiformis–Derived Bimodal Porous Nanocarbons via Self-Activation for High-Performance Supercapacitors. Front Energy Res 9:744133. https://doi.org/10.3389/fenrg.2021.744133
Chen H, Lu S, Gong F et al (2017) Stepwise Splitting Growth and Pseudocapacitive Properties of Hierarchical Three-Dimensional Co₃O₄ Nanobooks. Nanomater 7:81. https://doi.org/10.3390/nano7040081
Ejsmont A, Kadela K, Grzybek G et al (2023) Speciation of Oxygen Functional Groups on the Carbon Support Controls the Electrocatalytic Activity of Cobalt Oxide Nanoparticles in the Oxygen Evolution Reaction. ACS Appl Mater Interfaces 15:5148–5160. 10.1021/acsami.2c18403
Fan X, Sun Y, Ohlckers P et al (2019) Porous Thin-Wall Hollow Co₃O₄ Spheres for Supercapacitors with High Rate Capability. Appl Sci 9:4672. https://doi.org/10.3390/app9214672
Gaire M, Adireddy BSS, Chrisey D (2020) Ultra-long cycle life and binder-free manganesecobalt oxide supercapacitor electrodes through photonic nanostructuring. RSC Adv 10:40234–40243. https://doi.org/10.1039/D0RA08510C
Ghosh D, Lim J, Narayan R (2016) High Energy Density All Solid State Asymmetric Pseudocapacitors Based on Free Standing Reduced Graphene Oxide-Co₃O₄ Composite Aerogel Electrodes. ACS Appl Mater Interfaces 8:22253–22260. https://doi.org/10.1021/acsami.6b07511
Hong WL, Lin LY (2019) Studying the substrate effects on energy storage abilities of flexible battery supercapacitor hybrids based on nickel cobalt oxide and nickel cobalt oxide@nickel molybdenum oxide. Electrochim Acta 308:83–90. https://doi.org/10.1016/j.electacta.2019.04.023
Hu X, Tian X, Lin YW (2019) Nickel foam and stainless steel mesh as electrocatalysts for hydrogen evolution reaction, oxygen evolution reaction and overall water splitting in alkaline media. RSC Adv. 9:31563–31571. https://doi.org/.1039/C9RA07258F
Jagtap SV, Tale AS, Thakre SD (2017) Synthesis by Sol Gel Method and Characterization of Co3O4 Nanoparticles. Int J Res Eng Appl Sci 7:1–6. http://euroasiapub.org/journals.php
Jang GS, Akhtar SAMS, Kim E (2017) Electrochemical Investigations of Hydrothermally Synthesized Porous Cobalt Oxide (Co₃O₄) Nanorods: Supercapacitor Application. ChemistrySelect 2:8941–8949. https://doi.org/10.1002/slct.201701571
Kharade PM, Thombare JV, Babar AR et al (2018) Electrodeposited nanoflakes like hydrophilic Co₃O₄ as a supercapacitor electrode. J Phys Chem Solids 120:207–210. https://doi.org/10.1016/j.jpcs.2018.04.035
Khaldakar M, Butala D (2017) The Synthesis and Characterization of Metal Oxide Nanoparticles and Its Application for Photo catalysis. Int J Sci Res 7:499–504. http://www.ijsrp.org/research-paper-0317.php?rp=P636301
Li G, Mu Y, Huang Z et al (2021) Poly-active centric Co₃O₄-CeO₂/Co-NC composites as superior oxygen reduction catalysts for Zn-air batteries. Sci. China Mater. 64:73–84.
https://doi.org/10.1007
/s40843-020-1378-y Li S, Wang Y, Sun J (2020) Hydrothermal synthesis of Fe-doped Co₃O₄ urchin-like microstructures with superior electrochemical performances. J. Alloys Compd. 821:153507. https://doi.org/10.1016/j.jallcom.2019.153507
Li ZY, Bui PT, Kwak DH et al (2016) Enhanced electrochemical activity of low temperature solution process synthesized Co₃O₄ nanoparticles for pseudo-supercapacitors applications. Ceram Int 42:1879–1885. https://doi.org/10.1016/j.ceramint.2015.09.155
Liao Q, Li N, Jin S et al (2015) All-solid-state symmetric supercapacitor based on Co₃O₄ nanoparticles on vertically aligned graphene. ACS Nano 9:5310–5317. https://doi.org/10.1021/acsnano.5b00821
Liu F, Su H, Jin L et al (2017) Facile synthesis of ultrafine cobalt oxide nanoparticles for highperformance supercapacitors. J Colloid Interface Sci 505:796–804. https://doi.org/10.1016/j.jcis.2017.06.058
Ndambakuwa W, Ndambakuwa Y, Choi J et al (2021) Nanostructured nickel-cobalt oxide and sulfide for applications in supercapacitors and green energy production using waste water. Surf Coat Technol 410:126933. https://doi.org/10.1016/j.surfcoat.2021.126933
Nieto YP, Zaki A, Vidal K et al (2021) Development of Co₃-xNi_xO₄ materials for thermochemical energy storage at lower red-ox temperature. Sol Energy Mater Sol Cells 230:111194. https://doi.org/10.1016/j.solmat.2021.111194
Pal B, Krishnan SG, Vijayan BL et al (2018) In situ encapsulation of tin oxide and cobalt oxide composite in porous carbon for high-performance energy storage applications. J Electroanal Chem 817:217–225. https://doi.org/10.1016/j.jelechem.2018.04.019
Pinky SK, Ferdush Ara F, Kurny ASW et al (2015) Photo Degradation of Industrial Dye Using ZnO as Photo Catalyst. Inter J Innov Res Sci Eng Tech 4:9986–9992. 10.15680/IJIRSET.2015.0410097
Ramsundar RM, Debgupta J, Pillai VK et al (2015) Co₃O₄ nanorods—efficient non-noble metal electrocatalyst for oxygen evolution at neutral pH. Electrocatalysis 6:331–340. https://doi.org/10.1007/s12678-015-0263-0
Rani BJ, Raj SP, Saravanakumar B et al (2017) Controlled synthesis and electrochemical properties of Ag-doped Co₃O₄ nanorods. Int. J. Hydrog. Energy. 42:29666–29671. https://doi.org/10.1016/j.ijhydene.2017.10.051 Reena RS, Aslinjensipriya A, Jose M, (2020) Investigation on structural, optical and electrical nature of pure and Cr-incorporated cobalt oxide nanoparticles prepared via co-precipitation method for photocatalytic activity of methylene blue dye. J. Mater. Sci.: Mater. Electron. 31:22057–22074. https://doi.org/10.1007/s10854-020-04708-6
Ribeiro RAP, Lazaro SRD, Gracia L et al (2018) Theoretical approach for determining the relation between the morphology and surface magnetism of Co₃O₄. J Magn Magn 453:262–267. https://doi.org/10.1016/j.jmmm.2017.11.025
Saddeler S, Hagemann U, Schulz S (2020) Effect of the Size and Shape on the Electrocatalytic Activity of Co₃O₄ Nanoparticles in the Oxygen Evolution Reaction. Inorg Chem 59:10013–10024. https://doi.org/10.1021/acs.inorgchem.0c01180
Salunkhe AB, Khot VM, Phadatare MR et al (2012) Combustion Synthesis of cobalt ferrite nanoparticles – Influence of fuel to oxidizer ratio. J Alloys Compd 514:91–96. https://doi.org/10.1016/j.jallcom.2011.10.094
Shaheen N, Yousuf MA, Shakir I et al (2020) Wet chemical route synthesis of spinel oxide nano-catalysts for photocatalytic applications. Phys B Condens 580:411820. https://doi.org/10.1016/j.physb.2019.411820
Sharma M, Gaur A (2020) Cu Doped Zinc Cobalt Oxide Based Solid-State Symmetric Supercapacitors: A Promising Key for High Energy Density. J Phys Chem C 124:9–16. https://doi.org/10.1021/acs.jpcc.9b08170
Sriram B, Sathiyan A, Wang SF et al (2021) Synergistic effect of Co₃O₄ nanoparticles with Bauhinia vahlii dry fruits derived activated carbon on energy storage applications. J Solid State Chem 295:121931. https://doi.org/10.1016/j.jssc.2020.121931
Thorat GM, Jadhav HS, Seo JG (2017) Bi-functionality of mesostructured MnCo₂O₄ microspheres for supercapacitor and methanol electro-oxidation. Ceram Int 43:2670–2679. https://doi.org/10.1016/j.ceramint.2016.11.081
Ullah AKMA, Amin FB, Hossain A (2020) Tailoring surface morphology and magnetic property by precipitants concentrations dependent synthesis of Co₃O₄ nanoparticles. Ceram Int 46:27892–27896. https://doi.org/10.1016/j.ceramint.2020.07.167
UmaSudharshini A, Bououdina M, Venkateshwarlu M et al (2020) Low temperature solvothermal synthesis of pristine Co₃O₄ nanoparticles as potential supercapacitor. Surf Interfaces 19:100535. https://doi.org/10.1016/j.surfin.2020.100535
Vijayanand S, Kannan R, Potdar HS et al (2013) Porous Co₃O₄ nanorods as superior electrode material for supercapacitors and rechargeable Li-ion batteries. J Appl Electrochem 43:995–1003. 10.1007/s10800-013-0593-7
Warsi MF, Shaheen N, Sarwar MI et al (2021) A comparative study on photocatalytic activities of various transition metal oxides nanoparticles synthesized by wet chemical route. Desalin 211:181–195. 10.5004/dwt.2021.26463
Ye J, Zhai X, Chen L et al (2021) Oxygen vacancies enriched nickel cobalt based nanoflower cathodes: Mechanism and application of the enhanced energy storage. J Energy Chem 62:252–261. https://doi.org/10.1016/j.jechem.2021.03.030
Zallouz S, Rety B, Vidal L et al (2021) Co₃O₄ nanoparticles embedded in mesoporous carbon for supercapacitor applications. ACS Appl Nano Mater 4:5022–5037. https://doi.org/10.1021/acsanm.1c00522
Zhang J, Xu Q, Wang J et al (2021) Dual-defective Co₃O₄ nanoarrays enrich target intermediates and promise high-efficient overall water splitting. Chem Eng J 424:130328. https://doi.org/10.1016/j.cej.2021.130328

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The evaluation of the electrochemical properties of Co3O4 nanopowders synthesized by autocombustion and sol-gel methods

Status:

Journal Publication

Version 1

Abstract

Figures

1. Introduction

2. Materials and methods

2.1 Synthesis of Co₃O₄ via autocombustion and sol-gel methods

2.2 Characterization

2.3 Fabrication of working electrode (CV & GCD experiments)

3. Results and Discussions

3.1 TEM (Transmission Electron Microscopy) Analysis

3.2 XRD (X-Ray Diffraction) Analysis

3.3 BET (Brunauer–Emmett–Teller)) Analysis

3.4 X-ray Photoelectron Spectroscopy (XPS) analysis

3.5 Cyclic Voltammetry (CV)

3.6 Galvanostatic charge-discharge (GCD)

3.7 Electrochemical Impedance Spectra (EIS)

3.8 Stability cycles

4. Conclusions

Declarations

References

Status:

Journal Publication

Version 1

The evaluation of the electrochemical properties of Co3O4 nanopowders synthesized by autocombustion and sol-gel methods

Status:

Journal Publication

Version 1

Abstract

Figures

1. Introduction

2. Materials and methods

2.1 Synthesis of Co3O4 via autocombustion and sol-gel methods

2.2 Characterization

2.3 Fabrication of working electrode (CV & GCD experiments)

3. Results and Discussions

3.1 TEM (Transmission Electron Microscopy) Analysis

3.2 XRD (X-Ray Diffraction) Analysis

3.3 BET (Brunauer–Emmett–Teller)) Analysis

3.4 X-ray Photoelectron Spectroscopy (XPS) analysis

3.5 Cyclic Voltammetry (CV)

3.6 Galvanostatic charge-discharge (GCD)

3.7 Electrochemical Impedance Spectra (EIS)

3.8 Stability cycles

4. Conclusions

Declarations

References

Status:

Journal Publication

Version 1

2.1 Synthesis of Co₃O₄ via autocombustion and sol-gel methods