Adsorption of cysteine on metal(II) octacynaomolybdate(IV) at different pH values: Surface complexes characterization by FT-IR, SEM with EDXA, CHNS and Langmuir isotherm analysis

Abstract

The present study examine the adsorption of cysteine on series of metal octacyanomolybdates (MOCMos) such as Mn(II)-, Fe(II)-, Co(II)-, Ni(II)-, Cu(II)-, Zn(II)- and Cd(II)-OCMo(IV) at different concentration range of adsorbate, contact time to attain the equilibrium, quantity of adsorbent and influence of pH. Surface complexes are investigated using FT-IR, SEM with EDXA and CHNS analysis. The important findings of this work are adsorption of cysteine with MOCMo are pH dependent, binding groups of cysteine with MOCMo are carboxylate and sulfhydryl, and the effect of outer sphere metal ions present in the MOCMo with cysteine was also observed. Infra-red spectral studies of cysteine-MOCMo adducts revealed that adsorption takes place through interaction between adsorbate molecules and outer divalent ions of MOCMos.