1. 1University of Mysore, Department of Studies in Chemistry, Manasagangotri, Mysore 570 006, India
2. 2University of Mysore, Materials Science Center, Manasagangotri, Mysore 570 006, India
3. 3Nelson Mandela Metropolitan University, Summerstrand Campus, Department of Chemistry, University Way, Summerstrand, PO Box 77000, Port Elizabeth, 6031, South Africa