Chemistry / Kimya

Permanent URI for this collectionhttps://hdl.handle.net/11147/4072

Browse

Filters

1996 - 199912010 - 20131

Settings

Subject: search.filters.subject.Luminescence

Search Results

Now showing 1 - 2 of 2
  • Article
    Citation - WoS: 8
    Hydrogen Sulfide Determination by Solid Surface Luminescence
    (Springer Verlag, 1996) Eroğlu, Ahmet Emin; Volkan, Mürvet; Bayramlı, Erdal; Ataman, O. Yavuz; Mark, Harry B.
    In the analytical system suggested, atmospheric hydrogen sulfide reacts with the surface of a filter paper treated with aqueous cadmium chloride and yields a luminescent species whose intensity can be correlated with the analyte concentration in ambient air. It was shown that the luminescent species are CdS solid particles which were formed in a well defined size. The paper luminescence was also tried on polymeric surfaces; polyethyleneoxide, polyvinyl alcohol, ethylcellulose and carboxymethylcellulose were found to give a similar luminescence signal. The system can be used on the tip of an optical fiber for an irreversible, cumulative type of analytical device for hydrogen sulfide determination. The 3s detection limit for the paper luminescence detection system was 7.8 ppb H2S.
  • Article
    Citation - WoS: 26
    Citation - Scopus: 27
    Developing a Facile 1 Method for Highly Luminescent Colloidal Cdsxse1_x Ternary Nanoalloys†
    (Royal Society of Chemistry, 2013) Ünlü, Caner; Ünal Tosun, Gülçin; Sevim, Seçil; Özçelik, Serdar
    We report a facile method to synthesize highly luminescent colloidal CdSxSe1 xternary nanoalloys. The synthesis is achieved exactly in one-step, one-pot and at low temperature, by applying the two-phase thermal approach. The optical and structural properties of the nanoalloys were characterized by various techniques. Photoluminescence of the nanoalloys is tunable from 435 to 545 nm by either the size or the composition of the nanoalloys. Highly luminescent nanoalloys having quantum yields up to 90% were prepared. The hydrodynamic size of the nanoalloys can be varied from 1.4 to 10.0 nm by the reaction time. DLS measurements showed that the size distribution of the nanoalloys is monodispersed. TEM images confirmed the size and the size distribution of the nanoalloys. The sulfur fraction in the nanoalloy composition, measured by XRD and verified by EDX, is modulated from 0.17 to 0.95 by increasing the amount of thiourea in the chalcogenide mixture. The sulfur-rich nanoalloys are formed when the initial mole ratio of the chalcogenide (S : Se) is equal or higher than eleven-fold. The gradient and homogeneous internal structures are revealed by analysis of the alloy composition as a function of the growth time. We propose that the two-phase approach, a non-injection technique, is a facile and versatile method to develop highly luminescent CdSxSe1 x nanoalloys without an inorganic coating layer.