1. Department of Chemistry, SRM University Amravati-AP, Neerukonda, Mangalagiri, Guntur, 522240 Andhra Pradesh, India
2. Center for Nanofibers & Nanotechnology, Department of Mechanical Engineering, College of Design and Engineering, National University of Singapore, Singapore 117574, Singapore
3. Department of Physics, SRM University Amravati-AP, Neerukonda, Mangalagiri, Guntur, 522240 Andhra Pradesh, India