1. Department of Pure and Industrial Chemistry, Bayero University Kano, Kano, Nigeria
2. Department of Chemistry, Faculty of Science, University of Malaya, Kuala Lumpur, Malaysia
3. Institute of Nanotechnology and Catalysis (NanoCat), University of Malaya, Kuala Lumpur, Malaysia
4. Department of Mechanical Engineering, Faculty of Engineering, University of Malaya, Kuala Lumpur, Malaysia