Ferroelectric-Driven Charge Separation and Cobalt-Induced Defect Engineering in BaTiO₃/Co–ZnO Heterostructures for Efficient Visible-Light Photocatalysis

Authors

  • Danasabe Abdullahi Ibrahim Department of Physics, Nigerian Army University, Biu, Nigeria Author
  • Adam Usman Department of Physics, Modibbo Adama University, Yola, Nigeria Author
  • Ahmed D Abubakar Department of Physics, Modibbo Adama University, Yola, Nigeria Author

DOI:

https://doi.org/10.56919/usci.2651.022

Keywords:

BaTiO₃/Co–ZnO heterostructure, Visible-light photocatalysis, Ferroelectric polarization, Defect engineering, Dye degradation, Charge separation

Abstract

The development of efficient visible-light-driven photocatalysts remains critical for sustainable environmental remediation. In this study, a BaTiO₃/Co–ZnO heterostructure (S3) was investigated for the photocatalytic degradation of organic dyes under visible-light irradiation. Structural analysis based on simulated X-ray diffraction (XRD) patterns confirmed the successful formation of a composite system comprising perovskite BaTiO₃ and hexagonal Co–ZnO phases. Optical characterization using the Tauc method revealed a reduced bandgap of approximately 2.65 eV, indicating enhanced visible-light absorption compared to pristine ZnO. The photocatalytic performance of the S3 heterostructure was evaluated using crystal violet (CV), methylene blue (MB), and rhodamine B (RhB) as model pollutants. UV–Vis absorption spectra showed a progressive decrease in the characteristic absorption peaks, confirming efficient degradation. After 75 min of irradiation, degradation efficiencies of 99% (CV), 98% (MB), and 99% (RhB) were achieved, outperforming many previously reported ZnO-based photocatalysts. The degradation process followed pseudo-first-order kinetics with rate constants of 0.01775 min⁻¹ (CV), 0.02047 min⁻¹ (MB), and 0.01992 min⁻¹ (RhB) and strong correlation coefficients (R² = 0.927–0.983). The enhanced photocatalytic activity is attributed to the synergistic effects of ferroelectric polarization from BaTiO₃ and cobalt-induced defect states in ZnO, which facilitate efficient charge separation, suppress electron–hole recombination, and improve interfacial charge transfer. The internal polarization field promotes directional carrier migration, while defect states extend light absorption into the visible region. Reactive oxygen species, including superoxide (O₂•⁻) and hydroxyl radicals (•OH), play a dominant role in the degradation process. Overall, the BaTiO₃/Co–ZnO heterostructure demonstrates a highly efficient and robust photocatalytic system, highlighting the effectiveness of combining ferroelectric materials with defect-engineered semiconductors as a promising strategy for advanced environmental remediation.

References

Chen, X. and Mao, S.S. (2007) ‘Titanium dioxide nanomaterials: Synthesis, properties, modifications, and applications’, Chemical Reviews, 107(7), pp. 2891–2959. DOI: https://doi.org/10.1021/cr0500535

Chong, M.N., Jin, B., Chow, C.W.K. and Saint, C. (2010) ‘Recent developments in photocatalytic water treatment technology’, Water Research, 44(10), pp. 2997–3027. DOI: https://doi.org/10.1016/j.watres.2010.02.039

Cui, Y., Briscoe, J., Wang, Y., Tarakina, N. V., Dunn, S. (2017) ‘Enhanced Photocatalytic Activity of Heterostructured Ferroelectric BaTiO3/α-Fe2O3 and the Significance of Interface Morphology Control’, ACS Applied Materials & Interfaces, 9(29), pp.24518-24526. DOI: https://doi.org/10.1021/acsami.7b03523

Hill, N.A. (2000) ‘Why are there so few magnetic ferroelectrics?’, The Journal of Physical Chemistry B, 104(29), pp. 6694–6709. DOI: https://doi.org/10.1021/jp000114x

Ishaq, T., Ehsan, Z., Qayyum, A., Abbas, Y., Irfan, A., Al-Hussain, S. A., Irshad, M. A., and Zaki, M. E. A. (2024) ‘Recent Strategies to Improve the Photocatalytic Efficiency of TiO2 for Enhanced Water Splitting to Produce Hydrogen’, Catalysts, 14(10), 674. DOI: https://doi.org/10.3390/catal14100674

Kailun, C., Wenkui, D., Yuhan, H., Fazhou, W., John, L. Z., and Wengui L. (2025) ‘Photocatalysis for sustainable energy and environmental protection in construction: A review on surface engineering and emerging synthesis’, Journal of Environmental Chemical Engineering, 15(5), p.117529. DOI: https://doi.org/10.1016/j.jece.2025.117529

Liu, X., Lv, S., Fan, B., Xing, A., and Jia, B. (2019) ‘Ferroelectric Polarization-Enhanced Photocatalysis in BaTiO3-TiO2 Core-Shell Heterostructures’, Nanomaterials, 9(8), p.1116. DOI: https://doi.org/10.3390/nano9081116

Lovedonia, K. K., Edwin, M., Mpitloane, J. H., Wilson, M. S., Sadanand, P., and Daniel, M. (2026) ‘Green-Synthesized Co-Doped ZnO/Cellulose Hydrogel Nanocomposites for High-Efficiency Photocatalytic Degradation of Methylene Blue’, South African Journal of Chemical Engineering, p.100862. DOI: https://doi.org/10.1016/j.sajce.2026.100862

Low, J., Yu, J., Jaroniec, M., Wageh, S. and Al-Ghamdi, A.A. (2017) ‘Heterojunction photocatalysts’, Journal of Advanced Materials, 29(20), 1601694. DOI: https://doi.org/10.1002/adma.201601694

Mariam, E. M., Safiya, M., Dikra, A., Wafaa, B., Rachid, E., and Abdelhafid, E. (2025) ‘Engineering TiO2 photocatalysts for enhanced visible-light activity in wastewater treatment applications’, Journal of Tetrahedron Green Chem, 6, p.100084. DOI: https://doi.org/10.1016/j.tgchem.2025.100084

Qi, H., Kang, Y., Liu, J. A.. (2024) ‘Reducing the vacancies associated with ferroelectric polarization to promote photocatalytic overall water splitting’, Journal of Sci. China Chem. 67, pp.3258–3264. DOI: https://doi.org/10.1007/s11426-024-2152-5

Ramesh, R. and Spaldin, N.A. (2007) ‘Multiferroics: progress and prospects’, Nature Materials, 6(1), pp. 21–29. DOI: https://doi.org/10.1038/nmat1805

Rong, H., Wenbao, H., Bihan, S., Houfen, L., Rui, L., Sufang, W., Aijuan, Z. (2025) ‘Persulfate-assisted photocatalytic pollutant degradation on ferroelectric BaTiO3/CuFe2O4 material: Ferroelectric polarization enhanced electron transfer and persulfate activation’, Journal of Applied Catalysis B: Environment and Energy, 376, p.125452. DOI: https://doi.org/10.1016/j.apcatb.2025.125452

Wei, T. C., Sze, M. L., Trong-Ming, D., Yit, T. O. (2023) ‘Improved photocatalytic activity of zinc oxide through the formation of novel ternary tungsten trioxide/carbon nanotube/zinc oxide composite photocatalyst’, Journal of Materials Science and Engineering: B, 297, p.116774. DOI: https://doi.org/10.1016/j.mseb.2023.116774

Published

2026-03-26

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How to Cite

Ibrahim, D. A., Usman, A., & Abubakar, A. D. (2026). Ferroelectric-Driven Charge Separation and Cobalt-Induced Defect Engineering in BaTiO₃/Co–ZnO Heterostructures for Efficient Visible-Light Photocatalysis. UMYU Scientifica, 5(1), 267-275. https://doi.org/10.56919/usci.2651.022

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