Innovative Zn-Doped TiO₂ Catalysts for Adsorptive–Photocatalytic Removal of Polyethylene Microplastics

Authors

  • Mohammad Luqman Ismail Universiti Kuala Lumpur, Branch Campus Malaysian Institute of Chemical and Bioengineering Technology (UniKL MICET), Lot 1988 Vendor City, Taboh Naning, 78000 Alor Gajah, Melaka, Malaysia
  • Norzahir Sapawe Department of Chemical Engineering and Energy Sustainability, Faculty of Engineering, Universiti Malaysia Sarawak (UNIMAS), 94300 Kota Samarahan, Sarawak, Malaysia
  • Muhammad Farhan Hanafi Department of Chemical Engineering and Energy Sustainability, Faculty of Engineering, Universiti Malaysia Sarawak (UNIMAS), 94300 Kota Samarahan, Sarawak, Malaysia
  • Diyana Faziha Mohamad Universiti Kuala Lumpur, Branch Campus Malaysian Institute of Chemical and Bioengineering Technology (UniKL MICET), Lot 1988 Vendor City, Taboh Naning, 78000 Alor Gajah, Melaka, Malaysia
  • Norezatul Shahirah Ahmad Zamanhuri Universiti Kuala Lumpur, Branch Campus Malaysian Institute of Chemical and Bioengineering Technology (UniKL MICET), Lot 1988 Vendor City, Taboh Naning, 78000 Alor Gajah, Melaka, Malaysia
  • Mohammed Danish Department of Chemistry, Faculty of Science, Islamic University of Madinah (IUM), Abo Bakr Al Siddiq Road, Al Jamiah District, Madinah 42351, Kingdome of Saudi Arabia
  • Siti Fatimah Ibrahim School of Chemical and Process Engineering, University of Leeds, LS2 9JT Leeds, United Kingdom

Keywords:

Polyethylene microplastics, Zn-doped TiO₂, microwave-assisted synthesis, visible light photocatalysis, adsorption–photocatalysis, environmental remediation

Abstract

Polyethylene (PE) microplastics persist in aquatic systems, posing ecological and health concerns due to their high resistance to natural degradation. This work explores the application of microwave-assisted zinc-doped titanium dioxide (Zn–TiO₂) catalysts for the combined adsorption and photocatalytic removal of PE microplastics under visible light. Catalysts were synthesized through microwave modification and assessed across different pH levels, catalyst dosages, and initial PE concentrations. The highest photocatalytic efficiency (85%) was obtained under acidic conditions (pH 3) at an optimal dosage of 3 g/L with 10 mg/L of PE. Zn–TiO₂ exhibited superior performance compared to pristine TiO₂ and ZnO, demonstrating enhanced adsorption and photocatalytic activity attributed to the synergistic effect of Zn incorporation, which improved light utilization and reduced electron–hole recombination. Reusability tests confirmed good stability, with 70% efficiency retained after five cycles. These findings establish microwave-modified Zn–TiO₂ as a promising, durable, and sustainable photocatalyst for mitigating microplastic pollution in aqueous environments.

Author Biographies

Mohammad Luqman Ismail, Universiti Kuala Lumpur, Branch Campus Malaysian Institute of Chemical and Bioengineering Technology (UniKL MICET), Lot 1988 Vendor City, Taboh Naning, 78000 Alor Gajah, Melaka, Malaysia

luqman.ismail03@s.unikl.edu.my

Norzahir Sapawe, Department of Chemical Engineering and Energy Sustainability, Faculty of Engineering, Universiti Malaysia Sarawak (UNIMAS), 94300 Kota Samarahan, Sarawak, Malaysia

norzahir@unikl.edu.my

Muhammad Farhan Hanafi, Department of Chemical Engineering and Energy Sustainability, Faculty of Engineering, Universiti Malaysia Sarawak (UNIMAS), 94300 Kota Samarahan, Sarawak, Malaysia

hmfarhan@unimas.my

Diyana Faziha Mohamad, Universiti Kuala Lumpur, Branch Campus Malaysian Institute of Chemical and Bioengineering Technology (UniKL MICET), Lot 1988 Vendor City, Taboh Naning, 78000 Alor Gajah, Melaka, Malaysia

diyana.mohamad01@s.unikl.edu.my

Norezatul Shahirah Ahmad Zamanhuri, Universiti Kuala Lumpur, Branch Campus Malaysian Institute of Chemical and Bioengineering Technology (UniKL MICET), Lot 1988 Vendor City, Taboh Naning, 78000 Alor Gajah, Melaka, Malaysia

norezatul.zamanhuri01@s.unikl.edu.my

Mohammed Danish, Department of Chemistry, Faculty of Science, Islamic University of Madinah (IUM), Abo Bakr Al Siddiq Road, Al Jamiah District, Madinah 42351, Kingdome of Saudi Arabia

danish@iu.edu.sa

Siti Fatimah Ibrahim, School of Chemical and Process Engineering, University of Leeds, LS2 9JT Leeds, United Kingdom

s.f.b.ibrahim@leeds.ac.uk

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Published

2025-10-01

How to Cite

Ismail, M. L., Sapawe, N., Hanafi, M. F., Mohamad, D. F., Zamanhuri, N. S. A., Danish, M., & Ibrahim, S. F. (2025). Innovative Zn-Doped TiO₂ Catalysts for Adsorptive–Photocatalytic Removal of Polyethylene Microplastics. Semarak International Journal of Chemical Process Engineering, 5(1), 1–11. Retrieved from https://semarakilmu.my/index.php/sijcpe/article/view/784

Issue

Vol. 5 No. 1: December (2025)

Section

Articles