Preparation of cobalt-RuO2 nanocomposite modified electrode for highly sensitive and selective determination of hydroxylamine

- Facile synthesis of cobalt-RuO2 nanocomposite was prepared by electrodeposition method on steel substrate.
- The surface morphology, crystal orientation and the chemical composition were characterized.
- The cobalt- RuO2 nanocomposite exhibited excellent electrocatalytic activity towards hydroxylamine electrooxidation.
- Amperometry sensing of hydroxylamine showed very high sensitivity and lower detection limit.
- Selective determination of hydroxylamine was achieved in presence of other nitrogen containing interferrents.

Herein, we report the facile synthesis of cobalt and cobalt-RuO2 nanocomposite modified electrode using electrodeposition method and utilized as an electro catalyst for electro oxidation of hydroxylamine. The surface morphology and the chemical composition of cobalt and cobalt-RuO2 nanocomposite were examined using FESEM, TEM, EDAX and XPS analysis. FESEM images inferred that the cobalt Nano flakes are uniformly deposited on the mild steel substrate in which the ruthenium oxide nanoparticles are randomly incorporated. EDAX analysis also confirmed the presence of cobalt, ruthenium and oxides in the electrodeposits. The predominant orientation and the crystal structure were obtained from XRD patterns. The crystal growth is preferably in (100) plane corresponding to hexagonal closed packed structure of cobalt and the reflections of RuO2 particles are at 2θ = 28.00. The electro oxidation of hydroxylamine at pure cobalt and cobalt-RuO2 nanocomposite electrode was investigated with cyclic voltammetry (CV). The onset potential of hydroxylamine oxidation on cobalt-RuO2 electrode starts at −0.09 V which is comparatively lower than pure cobalt. In addition to that, upon increasing the hydroxylamine concentration, the anodic oxidation peak gets increased with the decrease in the catholic reduction peak suggesting that the proposed material had a good electro catalytic activity for the electro oxidation of hydroxylamine.

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