Photocatalytic activity of prepared ZnO/CuO nanocomposites and kinetic degradation study of methylene blue

In this manuscript, ZnO/CuO nanocomposites with different concentrations of CuO were synthesized using a simple hydrothermal method. The x-ray diffraction (XRD), X-ray fluorescence (XRF), atomic force microscope (AFM), UV–Vis spectrophotometer, and fluorescence spectrometers were used to study the physicochemical properties of nanocomposites. The crystallite size demonstrates a gradual growth ranging from 31 to 42 nm due to incorporating different contents of CuO with ZnO nanoparticles . The mean square roughness (Rms) decreased from 4.3 to 1.6 nm due to incorporating 10 wt% of CuO nanoparticles with ZnO nanoparticles, while the average particle size increased. The bandgap energy reduced gradually from 3.36 to 3.1 eV depending on the CuO nanoparticles' incorporation ratio. The kinetic degradation of methylene blue (MB) was investigated deeply under different conditions by analyzing and fitting the absorbance peaks of MB during degradation. Interestingly, the photocatalytic efficiency of pure ZnO nanoparticles during 90 min is 74.5%. ZnO nanocomposite with 10 wt% of CuO demonstrated a high dye degradation of about 97.15%. The FTIR analysis reveals that the C=N bond has a rapid dissolution compared to other bonds of MB during the photocatalyst process.