Photocatalytic activity of SnO-TiO composite nanoparticles modified with PVP.

Interface modified SnO-TiO composite nanoparticles were produced in two stages: first SnO nanoparticles were prepared by chemical precipitation in the presence of polyvinylpyrrolidone (PVP) and thermally treated at 500 °C then TiO was deposited on top of modified SnO and followed by a final annealing. As a consequence SnO-TiO composite nanoparticles get crystallized while PVP is decomposed into monomer units and other attached smaller molecular fragments. TGA coupled with FT-IR spectroscopy confirmed the presence of monomers and other moieties as a result of PVP thermal fragmentation.

The role of calcination temperature on structural and luminescence behaviour of novel apatite-based CaY (SiO)O: Ce,Tb phosphors.

A series of novel apatite-based CaY(SiO)O phosphors doped with Ce and Tb were synthesized by a solid-state reaction method at different calcination temperatures and times. The comparative results of thermal analysis (TG-DTA), FTIR, X-ray diffraction (XRD) and environmental scanning electron microscope (ESEM) reveal that the firing temperature for Ca Y (SiO)O:Ce, Tb was optimized to be 1200°C. The systematic studies on the influences of thermal treatment conditions on photoluminescence (PL) and cathodoluminescence (CL) properties were also reported.

Adsorption of heavy metal cations by Na-clinoptilolite: equilibrium and selectivity studies.

This paper summarizes the conclusions of experiments conducted on the adsorption of Cd(2+), Co(2+), Cu(2+), Mn(2+), Ni(2+), Pb(2+) and Zn(2+) onto zeolite. The focus of the experiments was to establish the influence of the initial pH of the contact solution as well as the selectivity of zeolite on the efficiency of the adsorption process. To this end, experimental adsorption isotherms were established for the pH values ranging from 1 to 4 by using the Na-form of clinoptilolite (particle size range 0.