Electrocatalytic properties of electropolymerized Ni(II)curcumin complex

The voltammetric behavior in alkaline solution of a nickel-based chemically modified electrode (poly-Ni(II)curcumin) prepared by oxidative electropolymerization of nickel-curcumin complex for electrooxidation of aliphatic alcohols was investigated by cyclic voltammetry and rotating disk technique (curcumin = 1,7-bis[4-hydroxy-3-methoxyphenyl]-1,6-heptadiene-3,5-dione). The dependence of the oxidation current on the alcohol concentration and on the number of redox centers Ni(II)/Ni(III) is discussed. From the fact that the oxidation current increases with the increase of film thickness it is evident that the electrocatalytic reaction occurs inside the polymer film. The system examined is a typical example of a redox polymer with 3D properties. It is also concluded that the reaction mechanism of alcohol oxidation is the case, according to the concept of Andrieux and Saveant, where the cross-exchange reaction is the limiting step. The mechanism of modifying the film formation has also been discussed.