1. Department of Materials and Energy Science and Engineering, School of Materials, Energy, Water and Environmental Sciences, The Nelson Mandela African Institution of Science and Technology, Arusha, Tanzania
2. Department of Physical and Environmental Sciences, Faculty of Science, Technology and Environmental Studies, The Open University of Tanzania, Dar es Salaam, Tanzania
3. Tabora Regional Centre, The Open University of Tanzania, Tabora, Tanzania
4. Department of Chemistry, Faculty of Science, University of Jeddah, Jeddah, Saudi Arabia
5. Department of Chemistry, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia