Removal of the Cd(II), Ni(II), and Pb(II) ions via their complexation with the uric acid-based adsorbent and use of the corresponding Cd-complex for the synthesis of tetrazoles

Abstract

The magnetic supported uric acid-based compound (Fe3O4@SiO2@CPTMS@UA) was prepared, characterized and used as a capable adsorbent for removal of the Cd(II), Ni(II) and Pb(II) ions from aqueous solution. The Freundlich and Langmuir adsorption isotherms have been used to evaluate the adsorption behaviors. The high correlation coefficient of the Langmuir model (R+2 > 0.99) reveals that the Langmuir model offers the better coordination with the experimental results and so the model of adsorption of Cd2+, Ni2+, and Pb2+ on the adsorbent is more compatible with the Langmuir model, and the maximum adsorption capacity for the Cd, Ni, and Pb ions are about 285.7, 45.06 and 145.09 mg/g. Then, the corresponding Cd-complex (Fe3O4@SiO2@CPTMS@ UA@Cd) was also prepared, characterized and applied as an efficient heterogeneous nano-catalyst for the synthesis of diverse tetrazoles.