Synthesis and application of γ-alumina nanopowders

Aluminum oxide (Al2O3) nanopowder was synthesized using AlCl3„ª6H2O as the starting material by the aqueous based precipitation method and applied in removal of Cr (VI) ion from aqueous solution. The characteristics of the sample were investigated by X-ray diffraction studies, DSC-TG analysis, and IR techniques. From the thermal studies the mass loss was found to be 45%. The study of the evolution of crystalline phases of obtained powders was accomplished through X-ray diffraction studies. XRD data showed that the sample calcined at 650¢XC has £^-Al2O3 phase. The crystallite size and particle size were rapidly changed over 1000„aC and cause the formation of £\-Al2O3 phase. FTIR results showed that the calcined nanoparticle were also free from surfactant. The prepared £^-Al2O3 nanopowders were applied for removal of Cr (VI) ions from aqueous solution. The effects of contact time on the extent of removal of Cr (VI) ions were also investigated. The results indicate that the prepared aluminum oxide via surfactant assisted route may have potential as novel, and effective adsorbent for removal of hexavalent chromium Cr(VI) ion from aqueous solution