Preparation of cobalt hydroxide modiflied glassy carbon electrode by film plating/cyclic voltammetry and its electrochemical behavior

Cobalt hydroxide modified glassy carbon electrode was prepared by a new method-film plating/cyclic voltammetry. Various factors affecting the electrocatalytic activity of cobalt hydroxide film were investigated, with the optimal time of cathodic enrichment and the optimal concentration of active species being 2 min and 9.90 x 10(-4) mol (.) L-1, respectively. The process and mechanism of film-forming were discussed. The anodic peak current i(pa)(0) of cobalt hydroxide film was proportional to scanning rate ( v = 0.60 V (.) s(-1)), indicating the characteristics of a surface adsorbed redox species corresponding to 0.5 monolayer. The resulting cobalt hydroxide film modified electrode had considerable stability and showed high electrocatalytic activity towards the oxidation of H2O2. The linear regression equation is Deltai(pa) (muA) = - 2.1036 + 2.3720 x 10(4) CH2O2 (mol (.) L-1) ( R = 0. 9990, n = 18) and the linear range for the determination of H2O2 is 1.43 x 10(-5) similar to 1.80 x 10(-2) mol (.) L-1 with a detection limit of 9.59 x 10(-6) mol (.) L-1 (3S/k).