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Department of Chemistry, Kalasalingam University, Krishnankoil-626 126, Tamilnadu, India E-mail : kanthi_somu@rediffmail.com Department of Chemistry, Ramco Institute of Technology, Rajapalayam-626 127, Tamilnadu, India Department of Chemistry, Thiagarajar College of Engineering, Madurai-625 115, Tamilnadu, India The adsorbent nano iron oxide (SNIO) was synthesized and essential characterstics were ascertained using FT-IR, SEM and EDAX techniques. Commercially Available Carbon (CAC) was activated further by acid treatment to enhance its adsorption capacity. Adsorption experiments were carried out by using batch method to compare the sorption behaviour of SNIO and CAC for the removal of PbII ions. The study was conducted on the basis of parameters such as a function of initial concentration of the adsorbate, adsorbent dosage, contact time and pH. Freundlich and Langmuir isotherm models have been tested.

Manganese doped zinc gallate powder was synthesised using a citrate gel method and subsequently deposited as a thin film by pulsed laser deposition technique at different temperatures on quartz and glass substrates. The luminescence behaviour of the deposited film was studied and the results reported. � 2005 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Phosphors are light emitting solids that play an important role in the lighting industry. The physics of doping suitable elements plays an equally important role in controlling the emission properties. The choice of host lattice is the key in controlling the charge transfer mechanism. Zn2SiO4 is a useful host material, and in this chapter we discuss on the effect of doping in various forms of this host material. Zn2SiO4:Mn powder (bulk) phosphors have been synthesized by sol-gel [1] and solid-state method, and thin films grown by pulsed laser deposition [2]. The optimization parameters like growth temperature, vacuum, and oxygen partial pressure (in case of thin films) that determine the luminescent efficiency of the phosphors will be highlighted. The defect and its related emission in ZnO encapsulated SiO2 nanocomposites [3] synthesized using urea assisted sol-gel techniques projecting toward the fabrication of UV-LED pumped white LED will be discussed in detail. � Springer India 2014.

A bright green light emitting Zn2 Si O4: Mn phosphor has been prepared at low temperature 800�C through gel combustion synthesis using zinc nitrate, manganese acetate, urea in a silica gel matrix. The structure and morphology of the phosphors using scanning electron microscopy along with thermogravimetric analysis/differential thermal analysis/Fourier transform infrared study along with X-ray diffraction, diffuse reflectance spectroscopy, and photoluminescence (PL) data show interesting trends with respect to the phase evaluation of Zn2 Si O4: Mn phosphor. Photoluminescent and crystalline properties are examined as a function of firing temperature and Mn concentration. Maximum PL intensity is observed at ?em =522 nm for 0.03 Mn2+ concentration, which can be attributed to the T14 (G) - A16 (S) transition of Mn2+ under short ultraviolet excitation. The PL emission intensity of these phosphors is found to be more superior to that of the corresponding samples prepared using the conventional solid state method implying the suitability of this route for the preparation of device worthy phosphor materials. � 2007 The Electrochemical Society.