Structural, Electrical and Electrochemical Characterizations of Perovskite Ni-Doped SrCoO3−δ

Perovskite SrCo1−yNiyO3−δ (0 ≤ y ≤ 0.4) oxides synthesized by sol–gel method were investigated. X-ray diffraction, thermogravimetric and differential thermal analysis, fourier transform infrared spectroscopy, scanning electron microscopy, electrical conductivity and electrochemical measurements, were used to characterize the structure, morphology, electrical and electrochemical properties of the samples. The studied compounds have rhombohedral crystal structure in the substitution range 0 ≤ y ≤ 0.4 and the solubility of Ni in the SrCoO3−δ was limited to y ≤ 0.3. Temperature dependence of electrical conductivity shows a semiconducting behavior. The conductivity increases with increasing nickel substitution and reaches a maximum for the composition of SrCo0.7Ni0.3O3−δ (19 S cm−1) at 300 °C. The electrochemical measurements indicate that the catalytic activity is strongly influenced by nickel doping. The highest electrode performance is achieved with large nickel content.