1. Department of Chemistry, D.G. Vaishnav College, Chennai 600106, India
2. Department of Chemistry, Auxillium College (Autonomous), Vellor 632006, India
3. Department of Materials Science, Central University of Tamil Nadu, Neelakudi, Thiruvarur 610005, Tamil Nadu, India
4. Department of Chemistry, St. Xavier’s College (Autonomous), Tirunelveli 627002, India
5. UNESCO-UNISA Africa Chair in Nanosciences/Nanotechnology Laboratories, College of Graduate Studies, University of South Africa (UNISA), Muckleneuk Ridge, P. O. Box 392, Pretoria 001, South Africa