Fabrication of some Quaternary Spinel StructureElectrodesfor PhotoelectrochemicalApplications

Abstract

In this study, nanostructuredZnNiCo2O4and MnNiCo2O4electrodes were fabricated by spray pyrolysis method and annealed at 550oCfor 2 h. The structural, optical, and Photoelectrochemical properties were studied. The structural properties were examined using X-ray diffraction (XRD). The resultsshow thatthe sampleshave a cubic spinel structures.The atomic percentage determined by (EDX) and the thickness (cross-section) of films measured by (FE-SEM), as well as the surface roughness measured through (AFM) are all used for analysis.The optical properties were investigated by UV-visible spectrophotometer, and the energy band gaps ofZnNiCo2O4 and MnNiCo2O4were estimated to be approximately2.2 and 2.4 eV respectively. The photoelectrochemical, comprising of photocurrent density, linear sweep voltammograms (LSV), and Mott-Schottky (MS), displayed flat band values of (1.5 eV and -0.55 eV) Vs NHE for ZnNiCo2O4and MnNiCo2O4 respectively, where the conduction band and valance band values of ZnNiCo2O4were (C. B= -0.6 eVand V.B= 1.6 eV ), while those of MnNiCo2O4were (C.B= -0.65 eV and V.B= 1.75 eV ). The corresponding photocurrent densities for ZnNiCo2O4and MnNiCo2O4were 35 μA/cm2and 50 μA/cm2, respectively