Structural, optical and conductivity studies of amorphous ZnxNi1-xO thin films along with wettability and photocatalytic tests

Abstract Non-crystalline zinc nickel oxide has been deposited on glass substrate using spray pyrolysis. The structural and optical properties were examined using XRD and UV–visible spectrophotometry. These films are characterized by a direct band gap and the optical band gap energy value is lying between 3.66 eV and 3.79 eV. The electrical conductivity was investigated at different temperatures (330–450 °C) by using the impedance spectroscopy technique in a frequency range from 5 Hz to 13 MHz. The value of s is dependent on temperature, which tends to decrease depending on the temperature. The temperature dependence of both the AC conductivity and the parameter s is interpreted by the correlated barrier hopping (CBH) model. These films revealed a hydrophilic character. Moreover, in the presence of these samples, a photodegradation of methyl blue (MB) and effective mineralization occurred; 14 mg/L of MB was degraded within 120 min. Finally, elements from the Lattice Compatibility Theory were presented in order to understand partial non-crystallization of the ZnO-NiO binary structure.