In the present study the activity of the Co with a fiber structure decorated by Pt or Au nanoparticles (denoted as Pt/Co_fiber and Au/Co_fiber) was investigated towards the electro-oxidation of hydrazine. At first, Co coating with a fiber structure and the thickness of ~3 µm was electroplated onto the Cu surface. Then, the Pt nanoparticles were deposited on the prepared Co_fiber/Cu by its immersion into the 1 mM H₂PtCl₆ + 0.1 M HCl solution at the temperature of 25 ^oC for 10-60 s, respectively, whereas Au nanoparticles were deposited on Co_fiber/Cu by its immersion into the 1mM HAuCl₄ + 0.1 M HCl for 10-300 s. Field Emission Scanning Electron Microscopy, Energy Dispersive X-ray Spectroscopy and Inductively Coupled Plasma Optical Emission Spectroscopy were used for determination of morphology, structure and composition of the prepared catalysts. The electrocatalytic properties of catalysts were evaluated with respect to the electro-oxidation of hydrazine in an alkaline medium by means of cyclic voltammetry and chrono-techniques.

It was found that the Pt loadings were 5, 15 and 29 µg cm^–2 in the prepared Pt(Co_fiber)/Cu catalysts after the immersion of Co_fiber/Cu into the platinum-containing solution for 10, 30 and 60 s, respectively. The Au loadings were 20, 28 and 96 µg
cm^–2 in the prepared Au(Co_fiber)/Cu catalysts after the immersion of Co_fiber/Cu into the gold-containing solution for 10, 60 and 300 s, respectively. The cobalt with a fiber structure decorated with the Pt or Au nanoparticles show enhanced electrocatalytic activity towards the electro-oxidation of hydrazine in an alkaline medium as compared to that of bare Co deposited on the Cu surface.

 Acknowledgment

 This research was funded by a Grant (No. TEC-06/2015) from the Research Council of Lithuania.