Cobalt nanoparticles as sacrificial templates for the electrodeposition of palladium nanomaterials in an ionic liquid, and its application to electrochemical sensing of hydrazine

We report on the electrodeposition of palladium nanomaterials in choline chloride-based ionic liquid ethaline. A glassy carbon electrode (GCE) was modified with cobalt nanoparticles (acting as sacrificial templates) and a GCE modified with palladium nanoparticles (PdNPs) were fabricated and used to study the electrocatalytic oxidation of hydrazine (N2H4). Scanning electron microscopy revealed that the PdNP modified GCE has a uniform morphology. Zero current potentiometry was used for in-situ probing the changes in interfacial potential of the oxidation of hydrazine. An amperometric study showed that the PdNP modified GCE possesses excellent electrocatalytic activity towards N2H4. The modified electrode displays a fast response (< 2 s), high sensitivity (74.9 mu A m(mol L-1)(-1) cm(-2)) and broad linearity in the range from 0.1 to 800 mu mol L-1 with a detection limit of 0.03 mu mol L-1 (S/N = 3).