<b>SYNTHESIS AND CHARACTERIZATION OF Ni_0.4Co_2.6O₄ SPINEL MIXED OXIDES POWDER: STUDY OF ITS SURFACE PROPERTIES BY VOLTAMMETRY, X-RAY, FTIR, UV-VIS-NIR SPECTROSCOPY AND SCANNING ELECTRON MICROSCOPY</b>

Abstract

Electrochemical studies were carried out on Ni 0.4 Co 2.6 O 4 powders prepared by sol-gel via propionic acid method using cyclic and steady state voltammetries. The oxide surface was characterized by scanning electron microscopy (SEM), X-ray diffraction, UV-vis-NIR and FTIR spectroscopies. The results showed that the formation of homogeneous oxide with a single spinel phase occurred at 350°C. The surface redox couple NiOOH/Ni(OH) 2 is confined on the surface material l.

Heterogeneous NiCo2O4@polypyrrole core/sheath nanowire arrays on Ni foam for high performance supercapacitors

“…3. It can be seen that the characteristic peaks of NiCo 2 O 4 appear at about 553 and 643 cm À1 , belonging to metaleoxygen MÀO vibrations of the NiCo 2 O 4 [35,36], the peaks at around 3413 and 1628 cm À1 are attributed to the vibrational mode of absorbed H 2 O [37,38], and the peak at 1383 cm À1 may be associated with the presence of physically adsorbed CO 2 [39]. In contrast, in the spectrum of NiCo 2 O 4 @PPy core/sheath nanowire arrays (Fig.…”