Electrochemical Behavior of Stable Cinder/Prussian Blue Analogue and Its Mediated Nitrite Oxidation

Prussian blue (PB) is electrochemically trapped directly on the interlayer resume of cinder-containing carbon paste electrodes (cinder/PB-CPEs). A UV-visible spectroscopic study gives supportive evidence for the formation of PB in the cinder matrix. This hybrid cinder/PB-CPE shows similar redox behavior to that of electrochemically synthesized PB film on the surface of a glassy carbon electrode. Nevertheless, the physical and electrochemical activities are comparatively superior over the classical PB electrodes. The electrochemical features, such as, high surface excess, positive site-site interaction parameter together with low film resistance result in good electrochemical activity and stability of the cinder/PB-CPE. The cinder/PB-CPE is further utilized for the mediated oxidation of nitrite. Mechanistic parameters, such as, anodic transfer coefficient, Tafel slope, and standard heterogeneous second order rate constant were evaluated as 0.52, 114.3 mV/decade, and 8.36 mol−1 dm3 s−1, respectively. The catalytic scheme was then extended to analytical applications with a linear range up to 1600 μM (regression coefficient=0.9996) and a detection limit (S/N=3) of 3.36 μM.