Clay Effect in the Electrochemical Stabilization of Colloidal CoO(OH) Applied as a Modified Electrode

In this work, a mixed material was prepared using a montmorillonite clay (denominated imported sodic, IS) modified with colloidal cobalt (Co). The obtained mixed material (ISCo) was characterized by X-ray diffractometry and simultaneous thermal analysis and used to modify the surface of a platinum electrode for electrochemical determination of oxalic acid. The electrochemical behavior of the ISCo material was evaluated by cyclic voltammetry and the performance as a sensor for oxalic acid was assessed by square wave voltammetry. The platinum electrode showed no response to peak current when the oxalic acid concentration was increased in the range of 4.99 x 10 -4 to 4.95 x 10 -3 mol L -1 . On the other hand, the platinum electrode modified with the mixed material presented a linear response in the studied range with a detection limit of 2.55 × 10 -4 mol L -1 . DOI: http://dx.doi.org/10.17807/orbital.v0i0.876