Abstract: An efficient separation of coordination compound of Ag(Ⅰ) was carried out taking TiO₂ nanoparticles as adsorbent, [S₂O₃]^2- anion as ligand and Flame Atomic Absorption Spectrophometer(FAAS) as detector to determine the concentration of Ag(Ⅰ). The effect of the crystalline structure of TiO₂ nanoparticles, pH values, adsorption time, initial concentration of Ag(Ⅰ), and some coexistent ion on the adsorption rate was systematically studied. The FTIR spectrum show that the coordination compound of Ag(Ⅰ) is physically adsorbed on the surface of TiO₂ nanoparticles. The adsorption isotherm of Ag(Ⅰ) on nano-TiO₂ show “S” type, which can be explained by the multi-molecular layer adsorption. The Ag(Ⅰ) adsorbed on TiO₂ nanoparticles could be eluted completely by mixed solution of nitric acid(1 mol/L) and sulfourea(2 g/L). The above experiment results would be valuable for using the nano-adsorbents to separate trace Ag(Ⅰ) in waste water.

Key words: TiO₂ nanoparticles, Nano-adsorbent, Adsorption isotherm