[1] Beni Suef Univ, Fac Postgrad Studies Adv Sci PSAS, Mat Sci & Nanotechnol Dept, Bani Suwayf 62511, Egypt
[2] Univ Zululand, Dept Chem, Private Bag X1001, ZA-3886 Kwa Dlangezwa, South Africa
[3] Univ KwaZulu Natal, Dept Chem, Private Bag X01, ZA-3209 Pietermaritzburg, South Africa