LED-enhanced photocatalytic reduction of hexavalent chromium by Cu-doped ZnO nanorods: kinetic modeling, cost analysis, and toxicity assessment

ABSTRACT

This study unveils the synthesis and application of Cu-doped ZnO nanorods (NR_S) as an efficient catalyst for the photocatalytic reduction of hazardous hexavalent chromium (Cr⁶⁺) in water. Synthesized via a simplified co-precipitation method, the NR_S demonstrated enhanced performance, achieving an 89.35% Cr⁶⁺ reduction efficiency under optimal conditions. The catalyst’s performance was significantly augmented in the presence of hydrogen peroxide (H₂O₂) and revealed a first-order kinetic model. Radical trapping experiments highlighted the pivotal role of hydroxyl radicals in the photocatalytic process. A comparative analysis of the NR_S with LED/ZnO and undoped ZnO underscores the superior efficiency of the Cu-doped variant. Moreover, the applicability of this system was validated in real water and wastewater matrices containing Cr⁶⁺, indicating its promising potential for industrial and environmental applications. An in vivo bioassay using Daphnia magna further confirmed the reduced toxicity post-treatment, underscoring the environmental friendliness of this innovative approach. The findings present Cu-doped ZnO nanorods as a promising, effective, and eco-friendly catalyst for the remediation of Cr⁶⁺ contaminated water, marking a significant stride towards sustainable and efficient water treatment solutions.

KEYWORDS:

• Cr⁶⁺ reduction
• visible light photocatalysis
• Cu-doped ZnO
• toxicity
• kinetic
• cost analysis

Acknowledgments

This research was supported by the Guilan University of Medical Sciences (GUMS) under Ethical code: IR.GUMS.REC.1396.234. The authors sincerely appreciate the Research Center of Health and Environment, GUMS, Rasht, Iran, for providing all the support for this work.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Author contributions

Kobra Ayagh: Data curation, Writing-original draft, Methodology, Software and formal analysis, Responding to reviewers and revising the manuscript. Mehdi Shirzad-Siboni: Supervision, Project administration, Data curation, Writing-original draft, Visualization, Conceptualization, Investigation, Methodology, Software and formal analysis, Responding to reviewers and revising the manuscript. Mahsa Tahergorabi: Writing-review & editing, Methodology and Investigation. Raf Dewil: Writing-review & editing, Methodology and Investigation. Azita Mohagheghian: Writing-review & editing, Methodology and Investigation. Kazem Godini: Writing-review & editing, Methodology and Investigation.

Data availability statement

The datasets used and/or analysed during the current study are available from the corresponding author on reasonable request.

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/03067319.2023.2297004

Correction Statement

This article has been republished with minor changes. These changes do not impact the academic content of the article.

Additional information

Funding

There is no funding for this study.