1. Department of Chemistry, University of Zululand, Private Bag X1001, KwaDlangezwa 3880, South Africa
2. Chemistry Department, University of Dar es Salaam, P.O. Box 35061, Dar es Salaam, Tanzania
3. Key Laboratory of Material Chemistry for Energy Conversion and Storage, Ministry of Education, Hubei Key Laboratory of Material Chemistry and Service Failure, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Luoyu Road No. 1037, Wuhan, China
4. Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland
5. Institute for Nanotechnology Innovation, Rhodes University, P.O. Box 94, Makhanda 6140, South Africa
6. Department of Chemistry, Rhodes University, P. O. Box 94, Makhanda 6140, South Africa
7. Department of Chemistry, Pittsburg State University, Pittsburg, KS 66762, USA