1. Department of Chemistry , University of Okara , Punjab , Pakistan
2. School of Materials Science and Engineering , Northwestern Polytechnical University , Xian , 710072 , P.R. China
3. Department of Chemistry , University of Karachi , Karachi , 75270 , Pakistan
4. Department of Chemistry , Abdul Wali Khan University , Mardan , Khyber Pakhtunkhwa , 23200 , Pakistan
5. Department of Conservation Studies , Hazara University , Mansehra , Khyber Pakhtunkhwa , 21120 , Pakistan
6. Department of Physics , University of Okara , Punjab , Pakistan