Research and Publications
Research Interests
My research interests cover the following topics:
Conversion of waste/biowaste into functional materials and energy within a circular economy framework.
Developing advanced functional materials for environmental catalysis.
Novel chemical technologies for water and wastewater treatment.
Waste-to-Resources
Waste to resources refers to the process of converting waste materials into valuable resources. Waste to catalytic material refers to the process of converting waste into catalysts, which are substances that increase the rate of chemical reactions. Catalysts are widely used in industry to produce chemicals, fuels, and other products. By converting waste into catalytic materials, the waste can be reused, reducing the need for new resources, and reducing waste in landfills. This process can help to conserve resources and reduce the environmental impact of waste disposal.
Carbon nanotubes (CNTs) can also be produced from waste materials through a process known as waste-derived carbon nanotube synthesis. This process involves the conversion of waste materials such as plastics, tires, or waste biomass into CNTs through thermal or catalytic methods. The waste derived CNTs can then be used as a reinforcement material in composites, as a component in electronics and energy storage devices, or in other applications where their unique mechanical, electrical, and thermal properties are required. The production of CNTs from waste not only helps to reduce the amount of waste in landfills, but also conserves resources and reduces the need for new raw materials in the production of CNTs.
Advanced materials for environmental catalysis
Environmental pollution due to recalcitrant organics is a global concern. Over the last decade, advanced oxidation technologies based on persulfate (peroxymonosulfate and peroxydisulfate) activation have been extensively developed for environmental decontamination owing to their advantages of being highly efficient, effective and eco-friendly. Generally, persulfate can be activated by using either external energy (e.g., UV, microwave, etc.), chemical (e.g., base, phenol, quinone, etc.), or transition metal catalyst (homogeneous or heterogeneous) to produce highly reactive transient species for aqueous pollutant destruction. However, the heterogeneous catalytic persulfate activation is preferred because of the following advantages: (1) no economic concern due to constant energy or auxiliary chemical requirement, (2) simple and versatile, and (3) ease of catalyst recovery after treatment. Currently, two classes of heterogeneous catalysts are developed, namely metal- and carbon-based catalysts. The metal-based catalysts are highly effective and efficient for persulfate activation. However, secondary pollution due to metal leaching during catalysis hinders their widespread application. To solve this issue, two strategies can be employed, namely designing metal-based catalysts with better stability, and developing carbon-based catalysts.
Representative Publications (2023-Present, * indicates as corresponding author) - A complete list can be found at my Google Scholar link
Z.Y. Choong, N. Subramaniam, M.F. Gasim, M.A. Mohamed Iqbal, C. He, K.Y.A. Lin, W.D. Oh*, Waste-derived MCM-41 as dual-functional support for cobalt ferrite: Performance as peroxymonosulfate activator for ciprofloxacin decontamination, Applied Surface Science, 645 (2024).
N.T. Sahrin, F.M. Ardo, U. Suparmaniam, A. Ramli, J.C. Sin, S.M. Lam, W.D. Oh, B.S. Chidi, H.S. Ng, M.K. Shahid, A.M. Tawfeek, K.S. Khoo, J.W. Lim, Enhanced microalgal hydrogen production subsisting on visible light TiO2 nanotubes photocatalyst pre-treated palm kernel expeller, International Journal of Hydrogen Energy, 54 (2024) 1307-1318.
G. Manickavasagam, C. He, K.Y.A. Lin, M. Saaid, W.D. Oh*, Recent advances in catalyst design, performance, and challenges of metal-heteroatom-co-doped biochar as peroxymonosulfate activator for environmental remediation, Environmental Research, 252 (2024).
J. El Gaayda, F.E. Titchou, I. Karmal, I. Barra, M. Errami, P.S. Yap, W.D. Oh, A. Iqbal, M. Sillanpää, M. Hamdani, R.A. Akbour, Application of grape seed and Austrocylindropuntia mucilage for the simultaneous removal of azo dye and turbidity from synthetic wastewater: Optimizing experimental conditions using Box-Behnken Design (BBD), Journal of Water Process Engineering, 58 (2024).
F. Khoerunnisa, Y.D. Yolanda, M. Nurhayati, H. Hendrawan, E.H. Sanjaya, J. Triwardono, W.D. Astuti, M. Handayani, W.D. Oh*, B.S. Ooi, pH-responsive chitosan/poly (vinyl pyrrolidone) based hydrogel composites: Antibacterial properties and release kinetics of diclofenac sodium, Journal of Drug Delivery Science and Technology, 92 (2024).
C. Wang, W. Sun, C. He, X. Ling, X. Zuo, W.D. Oh, C. Wu, H. Zhang, Enhancing hydrochar production and mitigating heavy metal risks in sewage sludge: The role of ultrasonic pretreatment in hydrothermal carbonization, Journal of Environmental Chemical Engineering, 12 (2024).
X.X. Lim, S.C. Low, K.Q. Tan, K.Y.A. Lin, F. Khoerunnisa, G. Lisak, W.D. Oh*, Investigating the role of Ca in NiMoCa catalyst on carbon nanotubes growth from face mask via one-pot synthesis, Journal of Analytical and Applied Pyrolysis, 179 (2024).
M.F. Gasim, N. Sivam, W.D. Oh*, PEROXYMONOSULFATE ACTIVATION USING NITROGEN-DOPED BIOCHAR FOR ACID ORANGE 7 REMOVAL IN WATER, Malaysian Journal of Analytical Sciences, 28 (2024) 10-20.
T.C. Khiem, N.N. Huy, E. Kwon, J. Lee, W.D. Oh, X. Duan, S. Wacławek, H. Wang, G. Lisak, F. Ghanbari, K.Y.A. Lin, Electron transfer-mediated enhancement of superoxide radical generation in fenton-like process: Key role of oxygen vacancy-regulated local electron density of cobalt sites, Applied Catalysis B: Environmental, 343 (2024).
A.R.D. Ahmad, S.S. Imam, R. Adnan, W.D. Oh, A.F. Abdul Latip, A.A.D. Ahmad, Fenton degradation of ofloxacin antibiotic using calcium alginate beads impregnated with Fe3O4-montmorillonite composite, International Journal of Biological Macromolecules, 229 (2023) 838-848.
T. Doan Trang, J. Lee, W.D. Oh, E. Kwon, H. Wang, Y. Fai Tsang, V.S. Munagapati, H. Yang, W.H. Chen, K.Y. Andrew Lin, Hollow-Structured N-doped carbon-embedded CoFe NanoAlloy for boosting activation of Monopersulfate: Engineered interface and heteroatom Doping-Induced enhancements, Journal of Colloid and Interface Science, 652 (2023) 1028-1042.
[T.C. Khiem, X. Duan, W.J. Liu, Y.K. Park, H.M. Bui, W.D. Oh*, S. Ghotekar, Y.F. Tsang, K.Y.A. Lin, MOF-templated hollow cobalt sulfide as an enhanced Oxone activator for degradation of UV Absorber: Key role of sulfur Vacancy-Induced highly active CoII sites, Chemical Engineering Journal, 453 (2023).
Y. Li, M. Huang, W.D. Oh, X. Wu, T. Zhou, Efficient activation of sulfite for reductive-oxidative degradation of chloramphenicol by carbon-supported cobalt ferrite catalysts, Chinese Chemical Letters, 34 (2023).
M.F. Gasim, Z.Y. Choong, P.L. Koo, S.C. Low, T.S. Hamidon, M.H. Hussin, K.Y.A. Lin, W.D. Oh*, Heteroatoms intra-actions and oxidant-pollutant competition over BC2O sites in N, S, B-tri-doped biochar for the nonradical activation of peroxymonosulfate, Journal of Water Process Engineering, 55 (2023).
F. Khoerunnisa, P.C. Amanda, M. Nurhayati, H. Hendrawan, W.W. Lestari, E.H. Sanjaya, M. Handayani, W.D. Oh*, J. Lim, Promotional effect of ammonium chloride functionalization on the performance of polyethersulfone/chitosan composite-based ultrafiltration membrane, Chemical Engineering Research and Design, 190 (2023) 366-378.
E. Saputra, B.A. Prawiranegara, M.W. Nugraha, W.D. Oh, H. Sugesti, P.S. Utama, 3D N-doped carbon derived from zeolitic imidazole framework as heterogeneous catalysts for decomposition of pulp and paper mill effluent: Optimization and kinetics study, Environmental Research, 234 (2023).
T.P. Vo, J. Rintala, L. Dai, W.D. Oh, C. He, The role of ubiquitous metal ions in degradation of microplastics in hot-compressed water, Water Research, 245 (2023).
X. Chen, H. Zhang, S. Xu, X. Du, K. Zhang, C.P. Hu, S. Zhan, X. Mi, W.D. Oh*, X. Hu, Z. Pan, Y. Bao, A Recyclable Co-Fe Bimetallic Immobilized Cellulose Hydrogel Bead (CoFeO@CHB) to Boost Singlet Oxygen Evolution for Tetracycline Degradation, Catalysts, 13 (2023).
M.F. Gasim, S.C. Low, C. He, K.Y.A. Lin, T.S. Hamidon, M.H. Hussin, W.D. Oh*, Atomically dispersed vanadium on g-C3N4 for effective ciprofloxacin degradation via peroxymonosulfate activation: Insights on the nonradical pathway and V redox cycles, Journal of Environmental Chemical Engineering, 11 (2023).
M.F. Gasim, A. Veksha, G. Lisak, S.C. Low, T.S. Hamidon, M.H. Hussin, W.D. Oh*, Importance of carbon structure for nitrogen and sulfur co-doping to promote superior ciprofloxacin removal via peroxymonosulfate activation, Journal of Colloid and Interface Science, 634 (2023) 586-600.
I.O. Saheed, E.N.M. Yusof, W.D. Oh, M.A.K.M. Hanafiah, F.B.M. Suah, Fabrication of chitosan@activated carbon composites in EmimAc for Cd(II) adsorption from aqueous solution: Experimental, optimization and DFT study, International Journal of Biological Macromolecules, 242 (2023).
Z.Y. Choong, M.F. Gasim, K.Y.A. Lin, T.S. Hamidon, H. Hussin, W.D. Oh*, Unravelling the formation mechanism and performance of nitrogen, sulfur codoped biochar as peroxymonosulfate activator for gatifloxacin removal, Chemical Engineering Journal, 451 (2023).
[23] E. Saputra, M. Wahyu Nugraha, B. Aditya Prawiranegara, N. Soraya Sambudi, W.D. Oh*, W. Peng, H. Sugesti, P. Setia Utama, Synergistic copper-modified covalent triazine framework for visible-light-driven photocatalytic degradation of organic pollutant, Environmental Nanotechnology, Monitoring and Management, 19 (2023).
Y. Bao, K. Xiao, S. Yue, M. Zhang, X. Du, J. Wang, W.D. Oh*, Y. Zhou, S. Zhan, Wastewater decontamination via piezoelectric based technologies: Materials design, applications and prospects, Surfaces and Interfaces, 40 (2023).
F. Khoerunnisa, M. Nurhayati, H. Herlini, Q.A.A. Adzkia, F. Dara, H. Hendrawan, W.D. Oh*, J. Lim, Design and application of chitosan-CuO nanocomposites synthesized via novel hybrid ionic gelation-ultrasonication methods for water disinfection, Journal of Water Process Engineering, 52 (2023).
P.L. Koo, Z.Y. Choong, C. He, Y. Bao, N.F. Jaafar, W.D. Oh*, Effect of metal doping (Me = Zn, Cu, Co, Mn) on the performance of bismuth ferrite as peroxymonosulfate activator for ciprofloxacin removal, Chemosphere, 318 (2023).
Z. Chen, A.I. Osman, D.W. Rooney, W.D. Oh, P.S. Yap, Remediation of Heavy Metals in Polluted Water by Immobilized Algae: Current Applications and Future Perspectives, Sustainability (Switzerland), 15 (2023).
K.Q. Tan, W.D. Oh, M.A. Ahmad, S.C. Low, Valorizing disposable face masks into non-condensable hydrocarbon gases via optimal reactor configurations in thermal pyrolysis, Journal of Analytical and Applied Pyrolysis, 175 (2023).
M. Hussein Abdurahman, A. Zuhairi Abdullah, W.D. Oh, N. Fazliani Shopware, M. Faisal Gasim, P. Okoye, A. Ul-Hamid, A. Rahman Mohamed, Tunable band structure of synthesized carbon dots modified graphitic carbon nitride/bismuth oxychlorobromide heterojunction for photocatalytic degradation of tetracycline in water, Journal of Colloid and Interface Science, 629 (2023) 189-205.
K.Q. Tan, M.A. Ahmad, W.D. Oh, S.C. Low, Valorization of hazardous plastic wastes into value-added resources by catalytic pyrolysis-gasification: A review of techno-economic analysis, Renewable and Sustainable Energy Reviews, 182 (2023).
A. Liangdy, W.J. Lee, Y. Bao, W.D. Oh, T.T. Lim, Hybrid process of persulfate-based advanced oxidation with MeOx-functionalized catalytic ceramic membrane for synergistic removal of micropollutants: Recent developments, new insights, and prospects, Chemical Engineering Journal, 466 (2023).
Z.U. Zango, K.S. Khoo, A. Garba, H.A. Kadir, F. Usman, M.U. Zango, W.D. Oh, J.W. Lim, A review on superior advanced oxidation and photocatalytic degradation techniques for perfluorooctanoic acid (PFOA) elimination from wastewater, Environmental Research, 221 (2023).
J. El Gaayda, Y. Rachid, F.E. Titchou, I. Barra, A. Hsini, P.S. Yap, W.D. Oh, C. Swanson, M. Hamdani, R.A. Akbour, Optimizing removal of chromium (VI) ions from water by coagulation process using central composite design: Effectiveness of grape seed as a green coagulant, Separation and Purification Technology, 307 (2023).
Z.Y. Choong, M.F. Gasim, T. Zhou, T.S. Hamidon, M.H. Hussin, F. Khoerunnisa, W.D. Oh*, The influence of B heteroatom concentrations on the physiochemical properties of N, B-co-doped biochar for peroxymonosulfate activation in ciprofloxacin removal, Journal of Water Process Engineering, 51 (2023).
R. Zhang, Y. Zhang, R. Goei, W.D. Oh, Z. Zhang, C. He, Sustainable utilization of Sedum plumbizincicola as superior hydrochar for efficient nutrients recovery, Journal of Environmental Management, 344 (2023).
T.C. Khiem, N.N. Huy, E. Kwon, S. Wacławek, A. Ebrahimi, W.D. Oh*, S. Ghotekar, Y.F. Tsang, W.H. Chen, K.Y.A. Lin, Tailoring oxygen vacancies in Co3O4 yolk-shell nanospheres via for boosted peroxymonosulfate activation: Single-electron transfer and high-valent Co-oxo species-dominated non-radical pathways, Chemical Engineering Journal, 476 (2023).
M.F. Gasim, Y. Bao, A.M. Elgarahy, A.I. Osman, A.H. Al-Muhtaseb, D.W. Rooney, P.S. Yap, W.D. Oh*, Peracetic acid activation using heterogeneous catalysts for environmental decontamination: A review, Catalysis Communications, 180 (2023).
C.W. Khew, K.H. Leong, L.C. Sim, A. Abd Aziz, C. Dai, W.D. Oh, S. Ibrahim, Sunlight mediated enhanced removal of metoprolol using graphitic carbon nitride (g-C3N4), Materials Research Proceedings, 2023, pp. 28-34.
X.X. Lim, S.C. Low, W.D. Oh*, A critical review of heterogeneous catalyst design for carbon nanotubes synthesis: Functionalities, performances, and prospects, Fuel Processing Technology, 241 (2023).
Intellectual Properties
Oh Wen Da, Lim Xiu Xian, Low Siew Chun, Mohamed Faisal Gasim, A sustainable one-pot synthesis process to produce carbon nanomaterials from carbonaceous waste, LY2023P04796, 03/10/2023.
Low Siew Chun, Oh Wen Da, Tan Kai Qi, Evolutionary Reactor Design: Energy-Efficient Pyrolysis for Enhanced Gas Production, LY2023P03920, 25/08/2023.
W.D. Oh, J.X. Lei, A. Veksha, A. Giannis, V.C.W. Chang, X. Hu (2018). Synthesis of nanostructured zinc oxide and application in warm fuel gas desulfurization. PCT application ref. no: WO2019004938A1.
A. Veksha, A. Giannis, W.D. Oh, V.C.W. Chang (2018). Reforming Catalyst with High Water-Gas Shift Activity and Resistance to Poisoning. PCT application ref. no: WO2019022666A1.
A. Veksha, A. Giannis, W.D. Oh, V.C.W Chang (2017). A process for production of Cr2O3/carbon nanocomposites from plastic pyrolysis gas. Technological disclosure at NTU reference no. TD/077/17.
W.D. Oh, J.X. Lei, A. Veksha, A. Giannis, T.T. Lim, G. Lisak (2017). Bifunctional Ni-Zn composites for catalytic water gas shift activity and sulfur removal in warm fuel gas. Technological disclosure at NTU reference no. TD/255/17.
P. Weerachanchai, K. Yin, A. Veksha, A. Ahamed, W.D. Oh, A. Giannis, G. Lisak (2018). Development Of Transition Metal-Solid Acid Catalyst For Catalytic Cracking Of Sublimate Substances. Technological disclosure at NTU reference no. 2018-091.