1. a Department of Chemistry, College of Natural and Computational Sciences, Mekelle University, PO Box 231, Mekelle, Ethiopia
2. b Department of Biological and Chemical Engineering, Mekelle Institute of Technology, Mekelle University, PO Box 1632, Mekelle, Ethiopia
3. c Department of Chemistry, College of Natural and Computational Sciences, Kebri Dehar University, Kebri Dehar, Ethiopia