Synergetic effect of Pd-Fe nanoclusters: electrocatalysis of nitrite oxidation

A nanocluster film of Pd-Fe oxide layers was deposited on a glassy carbon electrode (GCE) by continuous cyclic scanning in a PdCl2 and FeCl3 bath. The scanning electron micrograph (SEM) demonstrates that the films are uniform and the nanoclusters are homogeneously distributed on the GCE surface. The characterization of the surface structure is discussed based on XPS techniques. The electrochemical behavior of nitrite on the Pd-Fe/GC modified electrode is investigated. It is found that this modified electrode shows fast and substantial catalytic ability towards the oxidation of nitrite anions. This is possible due to the synergetic effect of Pd-Fe as opposed to that of a pure Pd or pure Fe-modified electrode. The detection limit is found to be 2 x 10(-6) M, and the linear concentration range is 6 x 10(-6)-5 x 10(-3) M. Possible interference from several common ions is tested. The method was successfully applied to the detection of nitrite in real samples.