Electrocatalytic determination of nitrite on a rigid disk electrode having cobalt phthalocyanine prepared in situ

This work reports an in situ cobalt(II) phthalocyanine (CoPc) synthesis on a SiO2/SnO2 (SiSn) matrix surface obtained by the sol-gel method and its electrocatalytic activity for oxidation of nitrite. A rigid disk electrode with SiSn/CoPc was used to study the electrooxidation of nitrite by the cyclic voltammetric, chronoamperometric techniques and differential pulse voltammetry (DPV). The adsorbed phthalocyanine electrocatalyzed nitrite oxidation at 0.73 V (versus SCE) using the DPV technique. The anodic peak current intensities, plotted from differential pulse voltammograms in 1 mol L-1 KCl for the concentration range 0.002 to 3.85 mmol L-1 of nitrite were linear, with a correlation coefficient of 0.998 and a detection limit of 0.95 mu mol L-1.