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ORIGINAL RESEARCH ARTICLE
Synergistic GO/MgO nanocomposites with enhanced charge separation for photocatalytic dye degradation
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1 Department of Physics, Faculty of Engineering and Applied Sciences, Riphah International University, Faisalabad, Punjab,
Pakistan
EER, 025480080 https://doi.org/10.36922/EER025480080
Received: 24 November 2025 | Revised: 11 December 2025 | Accepted: 24 December 2025 | Published online: 7 January 2026
© 2026 by the Author(s). This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution 4.0 International License ( https://creativecommons.org/licenses/by/4.0/ )
Abstract
The development of efficient and chemically stable photocatalysts with improved charge separation is critical for the remediation of dye-contaminated wastewater. In this study, graphene oxide–magnesium oxide (GO/MgO) nanocomposites with ultralow GO loadings (0–0.05 wt.%) were synthesized through a co-precipitation route and evaluated for ultraviolet (UV)-driven methylene blue (MB) degradation. X-ray diffraction (XRD) results were consistent with the retention of the cubic MgO phase (JCPDS 45-0946) with crystallite refinement from 20.26 to 13.26 nm, while the slight peak-position variations were more consistent with interfacial strain than definitive lattice substitution. UV–visible diffuse reflectance spectra revealed a red shift and bandgap reduction from 5.11 to 4.71 eV. Fourier transform infrared (FTIR) and Raman spectra showed GO-related functional signatures and a decrease in the ID/IG ratio (0.886 → 0.830), suggesting strengthened interfacial interactions with increasing GO loading. The optimized 0.05 wt.% GO/MgO sample achieved 91.6% MB degradation within 180 min and exhibited a 5.24-fold enhancement in the apparent pseudo-first-order rate constant (k = 0.00290 min−1) relative to pristine MgO (0.01518 min−1). Photocatalytic efficiency was maximized at pH 7–9 with a catalyst dosage of 0.75 g L−1, and post-reaction XRD/FTIR analysis indicated good structural stability. The enhancement is attributed to crystallite refinement and GO–MgO interfacial charge-transfer pathways inferred from consistent structural/optical–kinetic correlations.
Keywords
Graphene oxide
Magnesium oxide
Nanocomposites
Photocatalysis
Charge separation
Dye degradation
Funding
None.
Conflict of interest
The authors declare that they have no competing interests.
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