title: Turn-off of fluorescence of styryl phenanthrimidazole on doping ZnO nanoparticles with Ce(3+).
abstract: ZnO nanoparticles were doped with Ce(3+) by sol-gel synthesis and characterized by high-resolution scanning electron microscopy (HR-SEM), powder X-ray diffraction (XRD) and UV-visible diffuse reflectance (DRS) and photoluminescence (PL) spectroscopies. The dynamics of photoinduced electron injection from styryl phenanthrimidazole to Ce(3+)-doped ZnO nanoparticles has been studied by absorption, fluorescence and lifetime spectroscopic methods. Both the absorption and fluorescence quenching results suggest association between Ce(3+)-doped ZnO and the phenanthrimidazole. The free energy change (ΔGet) for electron injection has been calculated. The critical energy transfer distance between the phenanthrimidazole and Ce(3+)-doped ZnO nanoparticles has been deduced. In contrast to our earlier observation of enhancement of fluorescence of the phenanthrimidazole by ZnO nanoparticles, doping ZnO with Ce(3+) turns off its fluorescence. These findings provide a method to test the presence of Ce(3+) in ZnO nanocrystals.
authors: Department of Chemistry, Annamalai University, Annamalainagar 608002, Tamil Nadu, India.
authors: J
authors: J
authors: Jayabharathi
authors: Department of Chemistry, Annamalai University, Annamalainagar 608002, Tamil Nadu, India.
authors: I
authors: I
authors: JebaSingh
authors: Department of Chemistry, Annamalai University, Annamalainagar 608002, Tamil Nadu, India.
authors: A
authors: A
authors: Arunpandiyan
authors: Department of Chemistry, Annamalai University, Annamalainagar 608002, Tamil Nadu, India. Electronic address: karunakaranc@rediffmail.com.
authors: C
authors: C
authors: Karunakaran
mesh_terms: D065966:Absorption, Physicochemical; D002563:Cerium / Q000737:chemistry*; D007093:Imidazoles / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D010616:Phenanthrenes / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet; D013343:Styrenes / Q000737:chemistry*; D014961:X-Ray Diffraction; D015034:Zinc Oxide / Q000737:chemistry*
chemical_list: D007093:Imidazoles; D010616:Phenanthrenes; D013343:Styrenes; C000598662:styryl phenanthrimidazole; D002563:Cerium; D015034:Zinc Oxide
keywords: Ce–ZnO; Electron transfer; Phenanthrimidazole; Turn-off fluorescence; ΔG(et)