Verified Rigor RecordRigor Reviewed

Rigor-Reviewed Manuscript

Electrifying energy storage by investigating the electrochemical behavior of CoCr 2 O 4 /graphene-oxide nanocomposite as supercapacitor high performance electrode material · 10.1016/j.heliyon.2024.e40702

Name: Verified Rigor Record — Electrifying energy storage by investigating the electrochemical behavior of CoCr 2 O 4 /graphene-oxide nanocomposite as supercapacitor high performance electrode material · 10.1016/j.heliyon.2024.e40702
Item: Electrifying energy storage by investigating the electrochemical behavior of CoCr 2 O 4 /graphene-oxide nanocomposite as supercapacitor high performance electrode material · 10.1016/j.heliyon.2024.e40702
Rating: 67
Author: Αlpha¹

Paper source

Read full text

Αlpha¹ Editorial

This rigor review was examined and confirmed by Αlpha¹ Editorial · July 6, 2026

Αlpha¹ Rigor Review

Rigor Reviewed

WARN

Warnings to address · Other Study Type

Eight dimensions — click a segment for details

Critical

High-priority

Model-reported confidence: moderateReviewer agreement: lowEngine: 7.6.0Source: full text

Not verified in this report

References were not verified against Crossref/OpenAlex.
No reported statistical tests were found to recompute.
No data or code availability links were detected to verify.

This Αlpha¹ Rigor Review uses AI Rigor Reviewers trained on a curated corpus of high-fidelity and retracted papers, with expert supervision and curation. It can still make mistakes; verify each finding against the source before relying on it.

The paper presents a materials synthesis and electrochemical characterization study with a clear premise and detailed methods, but has significant gaps in data/code availability, key resource identification, and reporting transparency. The lack of a limitations section and vague data availability statement are the most critical weaknesses.

Evaluated on 8 dimensions; 4 dimensions (study design, biological variables, ethical approvals, statistical analysis) were deemed not applicable due to the materials science nature of the study. The reviewers diverged on study design and statistical analysis, but the synthesized judgment is not applicable for both. The copyedit pass flagged 30 issues, mostly grammar and clarity.

12 major claims checked against the paper's own evidence: 3 not fully backed by the presented evidence (unsupported or overstated).

6 integrity concerns flagged (0 high).

Rigor

Eight Dimensions1 pass · 2 warn · 1 fail

12 major claims1 unsupported2 overstated3 partial6 supported

The introduction cites 30+ references on supercapacitors, graphene, and spinel chromites, establishing context. It explicitly states that 'the integration of cobalt chromite...into graphene oxide...for supercapacitive applications is still an area that requires further investigation', which identifies a gap. The rationale linking the materials choice to improved conductivity and capacitance is logically presented.

Sub-criteria

prior work citedADEQUATE

premise rationaleADEQUATE

limitations addressedADEQUATE

Per reviewer (3) — the votes behind the verdict

PASSReviewer 1· 90% conf

The paper adequately cites prior work, provides a rational premise linking CoCr₂O₄/GO to supercapacitor applications, and acknowledges gaps in prior research.

Evidence

paraphrase[Introduction, paragraphs 1-4]

“The introduction reviews energy storage, supercapacitor types, graphene properties, and transition metal chromites, citing multiple references.”

direct quote[Introduction, paragraph 4]

“the integration of cobalt chromite (CoCr2O4) among transition metal chromites possessing spinel structure into graphene oxide (GO) networks for supercapacitive applications is still an area that requires further investigation”

paraphrase[Introduction, paragraphs 3-4]

“The paper argues that combining pseudocapacitive CoCr₂O₄ with conductive graphene oxide can improve conductivity and capacitance.”

WARNReviewer 2· 85% conf

The paper cites prior work on supercapacitors and similar nanocomposites but does not critically address limitations of prior research or describe how they are mitigated.

Evidence

direct quote[Introduction, paragraph 3 and 4]

“A recent study by Z. Orhan et al. reported the successful electrochemical fabrication of cobalt chromite/electro-reduced graphene oxide (CoCr2O4/ERGO) nanocomposite on nickel foam showing remarkable specific capacitance of 1610 F/g”

absence[Introduction]

The introduction does not discuss limitations of prior work or how this study addresses them.

direct quote[Introduction, last paragraph]

“This study reports successful synthesis of CoCr2O4/graphene-oxide nanocomposite using co-precipitation method.”

PASSReviewer 3· 90% conf

The paper establishes a clear scientific foundation by citing prior work on supercapacitors and chromite materials, and provides a logical rationale for the study.

Evidence

direct quote[Introduction, paragraph 1-6]

“Supercapacitors can be broadly classified into two categories: electric double layer capacitors (EDLCs) and pseudocapacitors (PCs) ...”

direct quote[Introduction, paragraph 6]

The paper does not involve randomization, blinding, power analysis, replicate distinction, inclusion/exclusion criteria, outlier handling, controls, or independent replication. As a materials synthesis study, these design elements are not applicable.

Sub-criteria

controlsN/A

power analysisN/A

blinding levelsN/A

outlier handlingN/A

randomization unitN/A

inclusion exclusionN/A

randomization methodN/A

replicate distinctionN/A

independent replicationN/A

Per reviewer (3) — the votes behind the verdict

WARNReviewer 1· 85% conf

The study design is largely descriptive for a materials synthesis and electrochemical testing paper; several expected elements for such a study are not reported, particularly regarding replication, blinding, and randomization, which are not applicable here, but power analysis, inclusion/exclusion criteria, and outlier handling are also missing.

Evidence

absence[Methods, section 2]

No power analysis or sample-size calculation is reported.

absence[Methods, section 2.4]

No explicit controls are described.

absence[Results and Conclusion]

No statement on independent replication is provided.

N/AReviewer 2· 90% conf

This is a materials characterization study with no experimental design elements such as randomization, blinding, or power analysis; hence most design sub-criteria are not applicable.

Evidence

absence[Methods]

No randomization, blinding, or power analysis described.

absence[Methods]

No statement of biological vs technical replicates.

direct quote[Methods section 2.3]

“To fabricate the CoCr2O4/GO nanocomposite, 50 mg of the synthesized GO was ultrasonically dispersed in 20 mL deionized water for 1 h, yielding a uniform suspension.”

N/AReviewer 3· 95% conf

The study is a synthesis and characterization experiment with no elements of interventional or observational design applicable to the rigor criteria.

Evidence

absence[Methods, sections 2.1-2.4]

No randomization, blinding, or other design elements are reported.

The study involves the synthesis and electrochemical testing of a nanocomposite material. There are no animal or human subjects, cell lines, or organisms. Therefore, all sub-criteria are not applicable.

Sub-criteria

demographicsN/A

sex reportedN/A

sex justifiedN/A

age weight healthN/A

housing conditionsN/A

species strain sourceN/A

Per reviewer (3) — the votes behind the verdict

N/AReviewer 1· 100% conf

This is a materials science study with no biological subjects; no biological variables are relevant.

Evidence

absence[Entire manuscript]

No biological subjects are used in this study.

N/AReviewer 2· 95% conf

No biological subjects, organisms, or cell lines are used; this is a materials synthesis and electrochemical study.

Evidence

absence[Methods]

No biological variables are reported; study is purely materials science.

N/AReviewer 3· 100% conf

The study does not involve any biological subjects, tissues, or organisms, so biological variables are not applicable.

Evidence

absence[Entire paper]

No biological subjects are used.

The paper reports on chemical synthesis and electrochemical characterization of a nanocomposite. No human participants, animals, or biological samples were used. All chemicals were purchased commercially. Therefore, no ethics approval is needed.

Sub-criteria

iacuc statementN/A

informed consentN/A

irb ethics statementN/A

regulatory complianceN/A

Per reviewer (3) — the votes behind the verdict

N/AReviewer 1· 100% conf

This study involves no human or animal subjects, tissues, or non-public identifiable data; ethical approvals are not required.

Evidence

direct quote[Methods, section 2.1]

“The compounds utilized in the synthesis, purchased from Sigma-Aldrich includes Chromium(III) nitrate nonahydrate...”

N/AReviewer 2· 95% conf

The study involves no human or animal subjects, only chemical reagents and synthesized nanomaterials; no ethics approval is required.

Evidence

absence[Methods]

No human or animal subjects involved.

N/AReviewer 3· 100% conf

The study does not involve human or animal subjects, tissues, or non-public identifiable data, so ethical approvals are not applicable.

Evidence

absence[Entire paper]

No human or animal subjects mentioned.

The chemicals (e.g., Cr(NO3)3·9H2O, Co(NO3)2·6H2O) are listed with vendor (Sigma-Aldrich) and purity (~99%), which is adequate for reagents. Software tools (e.g., Image J, Gamry Potentiostat) are named but without version numbers, making them reported_but_inadequate. Antibodies, cell lines, and organisms are not used and are marked not_applicable. The nanocomposite is not a standardized biological resource.

Sub-criteria

mycoplasma testingN/A

reagents identifiedADEQUATE

organisms identifiedN/A

antibodies identifiedN/A

cell line authenticationN/A

software tools identifiedINADEQUATE

Per reviewer (3) — the votes behind the verdict

WARNReviewer 1· 80% conf

Key reagents and software are identified, but several limitations exist: the investigational product (nanocomposite) is not assigned a lot/batch number, key instruments are under-identified (no model numbers for SEM, Raman, PL), and the Gamry potentiostat model is not given.

Evidence

direct quote[Methods, section 2.1]

“Chromium(III) nitrate nonahydrate (Cr(NO3)3·9H2O, 99%), Cobalt(II) nitrate hexahydrate (Co(NO3)2·6H2O, 99%)...”

direct quote[Methods, section 2.4]

“XRD analysis was performed on a Brucker D-8 X-ray Diffractometer...SEM operating at 20 kV. Raman analysis was performed on a DONGWO OPTRON system with a 532 nm laser excitation.”

direct quote[Results, section 3.2]

“spherical nanoparticles formation with 3.53 nm average grain size as calculated using Image J software.”

WARNReviewer 2· 85% conf

Chemical reagents are listed with purity/information, and software is identified but without versions; antibodies, cell lines, and organisms are not applicable. The investigational product (the nanocomposite) is synthesized, not a purchased reagent.

Evidence

direct quote[Section 2.1]

“The compounds utilized in the synthesis, purchased from Sigma-Aldrich includes Chromium(III) nitrate nonahydrate (Cr(NO3)3·9H2O, 99 %)...”

direct quote[Section 2.4 and 3.2]

“morphological examination was conducted using a TESCAN VEGA 3 SEM operating at 20 kV”

absence[Section 3.2 and 2.4]

No version specified for Image J or Gamry software.

FAILReviewer 3· 60% conf

Key reagents and software are identified but without catalog numbers or version numbers, making them inadequately reported.

Evidence

direct quote[Section 2.1, Chemicals and reagents]

“The compounds utilized in the synthesis, purchased from Sigma-Aldrich includes Chromium(III) nitrate nonahydrate (Cr(NO3)3·9H2O, 99%), Cobalt(II) nitrate hexahydrate (Co(NO3)2·6H2O, 99%)...”

direct quote[Section 2.4, Instrumentation and Section 3.2]

“using Image J software”

No p-values, confidence intervals, or statistical tests are reported. The data are presented as numerical values (specific capacitance, energy density) without statistical comparisons. Thus, the statistical analysis dimension is not applicable.

Sub-criteria

tests namedN/A

exact p valuesN/A

effect sizes ciN/A

data presentationN/A

software identifiedN/A

assumptions verifiedN/A

mathematical plausibilityN/A

Per reviewer (3) — the votes behind the verdict

N/AReviewer 1· 70% conf

The study uses electrochemical measurements (CV, GCD, EIS) without inferential statistical tests; no formal hypothesis testing is performed.

Evidence

absence[Results, section 3.4]

No inferential statistical tests are reported.

WARNReviewer 2· 75% conf

The statistical analysis is minimal; most sub-criteria are not reported or not applicable. No tests for normality, exact p-values, effect sizes, or confidence intervals are given. Software is not identified for statistics.

Evidence

absence[Results / Section 3.4]

No inferential statistics or p-values reported.

absence[Methods]

Statistical software not stated.

direct quote[Table 4]

“Table 4 Specific capacitance (F/g) in 1M KOH and 0.1M H2SO4.”

N/AReviewer 3· 95% conf

The paper does not perform any inferential statistical tests; it reports descriptive values (capacitance, etc.) without hypothesis testing.

Evidence

absence[Results sections 3.4.1-3.4.4]

No statistical tests or p-values are reported.

The paper states: 'Data used is confidential and will be made available on request.' This is a vague statement without a platform, conditions, or timeframe, which qualifies as reported_but_inadequate. No repository deposit, accession numbers, or code sharing are mentioned. For a computational/materials science study, this is a significant gap.

Sub-criteria

code sharingNOT REPORTED

accession numbersNOT REPORTED

repository depositNOT REPORTED

data availability statementINADEQUATE

Per reviewer (3) — the votes behind the verdict

FAILReviewer 1· 95% conf

No data or code are provided; the data availability statement is vague and provides no concrete access mechanism.

Evidence

direct quote[Data and code availability statement]

“Data used is confidential and will be made available on request.”

absence[Data and code availability statement]

No repository deposit or accession numbers are provided.

absence[Entire manuscript]

No code sharing is mentioned.

FAILReviewer 2· 90% conf

The data availability statement is vague ('on request'), no repository deposit or accession numbers are provided, and no code is shared.

Evidence

direct quote[Data and code availability statement]

“Data used is confidential and will be made available on request.”

absence[Entire paper]

No repository deposit, accession numbers, or code repository mentioned.

FAILReviewer 3· 70% conf

The data availability statement is vague and does not provide a concrete access route; no repository deposit or code sharing is reported.

Evidence

direct quote[Data and code availability statement, end of paper]

“Data used is confidential and will be made available on request.”

Methods are quite detailed (synthesis, characterization, electrochemical setup). Limitations are implicitly discussed (e.g., capacitance retention decreases due to CoCr₂O₄ dissolution), but no formal limitations section exists. Conclusions are proportional to evidence (no overclaiming). Funding and COI are disclosed. Trial registration is not applicable. No reporting guideline (e.g., ARRIVE, CONSORT) is mentioned.

Sub-criteria

funding coiADEQUATE

trial registrationN/A

reporting guidelineNOT REPORTED

methods completenessADEQUATE

all outcomes reportedINADEQUATE

limitations discussedINADEQUATE

conclusions proportionalADEQUATE

Per reviewer (3) — the votes behind the verdict

WARNReviewer 1· 85% conf

Methods are detailed enough for replication, and limitations are partially discussed, but the paper lacks a reporting guideline, mentions no trial registration (not applicable), and does not explicitly state that all outcomes are reported.

Evidence

direct quote[Declaration of competing interest]

“The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.”

absence[Entire manuscript]

No reporting guideline is mentioned.

paraphrase[Conclusion, paragraph 2]

“The paper mentions that capacitance retention decreases after 100 cycles due to dissolution of CoCr₂O₄ ions, which is a limitation.”

WARNReviewer 2· 80% conf

Methods are detailed enough for replication, limitations are not discussed, and no reporting guideline checklist is referenced. Trial registration and outcome pre-specification are not applicable.

Evidence

direct quote[Sections 2.1-2.4]

“To fabricate the CoCr2O4/GO nanocomposite, 50 mg of the synthesized GO was ultrasonically dispersed in 20 mL deionized water for 1 h”

absence[Discussion/Conclusion]

No limitations section or discussion of study weaknesses.

direct quote[Declaration of competing interest, Acknowledgement]

“The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.”

PASSReviewer 3· 85% conf

The methods are detailed, all outcomes are reported, and conclusions are proportional to the evidence, but limitations and funding sources are not reported.

Evidence

direct quote[Section 2, Materials and methods]

“To fabricate the CoCr2O4/GO nanocomposite, 50 mg of the synthesized GO was ultrasonically dispersed in 20 mL deionized water for 1 h...”

absence[Section 4, Conclusion]

No limitations section is present.

direct quote[CRediT authorship contribution statement]

“Akram Ibrahim: Resources, Funding acquisition.”

30 copyedit issues flagged (7 major): mostly grammar, clarity, consistency.

Αlpha¹ Rigor Action ItemsFinal pass before journal submission

The published paper has moderate robustness but is weakened by the lack of accessible data and code, missing limitations discussion, and incomplete resource identification. An informed reader should weigh these gaps when interpreting the results; a correction or independent re-analysis would be warranted to address the data availability and replication concerns.

1.
HIGHdata code
Replace the vague data availability statement with a concrete plan: deposit raw data (XRD, CV, GCD, EIS) in a public repository (e.g., Zenodo, Figshare) and provide a DOI in the Data and code availability statement.
The current statement 'Data used is confidential and will be made available on request' is insufficient for reproducibility and is a major rigor gap.
2.
HIGHreporting
Add a dedicated Limitations section (e.g., after Results or in Discussion) discussing sources of error, stability over longer cycling, and generalizability to other electrolytes.
The paper currently lacks any discussion of study limitations, which is a key element of reporting transparency.
3.
HIGHrigor
In the Introduction, add a paragraph explicitly describing limitations of prior CoCr2O4/GO studies and how this work addresses them (e.g., improved stability, higher capacitance).
The current introduction does not critically address limitations of prior work, weakening the scientific premise.
4.
HIGHreporting
In the Conclusion, temper the claim of 'superior' or 'exceptional' performance to what the evidence shows, e.g., 'promising for further investigation', and note the limited comparison set in Table 5.
The claim of superiority is overstated given the narrow comparison set and lack of benchmarking under identical conditions.
5.
HIGHreporting
In the Abstract and Introduction, remove or qualify the claim that the three-step fabrication method is 'novel', as the individual methods (Hummer's, sol-gel, co-precipitation) are standard.
The claim of novelty is unsupported and could mislead readers.
6.
HIGHrigor
In Methods, state whether the reported capacitance values are from a single test or multiple replicates; if no replicates, acknowledge this and discuss potential variability.
The lack of replicate information undermines the reliability of the reported values.
7.
HIGHrigor
In Methods, add catalog numbers for all chemicals purchased from Sigma-Aldrich in Section 2.1.
Catalog numbers are essential for reproducibility of reagents.
8.
HIGHrigor
In Methods, specify version numbers for all software used (Image J, Gamry Framework) in Section 2.4.
Software version numbers are necessary for reproducibility of data analysis.
9.
HIGHreporting
In Methods, clarify the relationship between the GCE area (0.076 cm²) and the surface area stated in the abstract (0.068 cm²); explain if the latter is the electrochemically active surface area.
The internal contradiction between these two values could confuse readers and needs resolution.
10.
MEDIUMcopyedit
In Methods, section 2.2, clarify 'until neutrality was achieved' to 'until the washings reached neutral pH'.
The original phrasing is ambiguous.
11.
MEDIUMcopyedit
In Methods, section 2.4, correct subject-verb agreement: 'Electrochemical analysis was conducted' and add articles for electrode descriptions.
Grammar errors reduce clarity.
12.
MEDIUMcopyedit
In Results, section 3.4.4, clarify the energy density formula: E = (1/2) * C_sp * (ΔV)^2 / 3.6, and note that ΔV should be in volts.
The equation formatting is ambiguous and could lead to misinterpretation.
13.
MEDIUMcopyedit
Throughout the manuscript, correct the typo 'comoparable' to 'comparable' (Abstract, Introduction).
Typographical errors undermine professionalism.
14.
MEDIUMcopyedit
In Results, section 3.4.3, correct 'Randles-Sevick' to 'Randles-Sevcik' for consistency.
Spelling inconsistency in a named equation.
15.
LOWcopyedit
In Table 5, ensure consistent formatting of chemical formulas (e.g., NaCr2O4/GO instead of NaCr 2 O 4 /GO).
Inconsistent formatting detracts from readability.

Full text (30,028 chars)Analyzed: Jul 6, 2026

Αlpha¹ assesses methodological rigor, not the importance of the findings. See how we calibrate →