engleski

Electrochemical processes of some metal ions on the mercury electrode in aqueous solution of tri- n-butyl phosphate

The influence of the adsorbed layer of tri-n-butyl phosphate on the reduction of Tl(I), U(VI), Pb(II), Cd(II), Cu(II) and In(III) was investigated by means of polarography and double potential-step chronocoulometry. The presence of TBP does not influence the reduction wave of Tl(I) but it shifts the wave of In(III), in chloride media, towards the desorption potential of TBP. No adsorption of the reactant was found by chronocoulometric measurements for the reduction of U, Tl, Cd, and Pb in the presence of adsorbed TBP. From the i-t curves for Pb, Cd and Cu it is evident that the inhibition of the electrode process on the covered surface increases by lowering pH of the solution and by increasing the bulk concentration of TBP. The adsorbed TBP most probably affects chemical reactions, such as dehydration, which could be involved in the electrochemical process of Cd, Pb and Cu. The possible effect of the formed amalgam should also be considered.

electrochemistry ; metal ions ; tri-n-butyl phosphate, TBP ; polarography ; chronocoulometry

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