ZnO-CuO Nanocomposites with Improved Photocatalytic Activity for Environmental and Energy Applications

摘要

A hydrothermal technique has been applied to synthesize ZnO-CuO nanocomposites that show very high photocatalytic efficiency under specific conditions. The structural, optical, and molecular vibrational properties of the nanocomposite samples were characterized by x-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), photoluminescence, ultraviolet-visible (UV-Vis) spectroscopy, and Raman spectroscopy. High-resolution SEM and Rietveld analysis of the XRD data confirm the nanocomposite structure of ZnO-CuO with different ratios of ZnO and CuO phase contents. Raman spectra of the nanocomposites consist of optical vibrational modes of both ZnO and CuO. The unique photoluminescence spectra exhibited characteristic peaks in the visible range, confirming enhanced absorbance in the visible region of the solar spectrum. The photocatalytic activity of the synthesized samples was studied using degradation of methylene blue dye under UV-Vis illumination, revealing photocatalytic efficiency of 56% for the best nanocomposite sample. We also have studied the growth mechanism of the nanocomposite samples, the role of the nanocomposite as a photocatalytic material for wastewater decontamination based on its unique band structure, and the efficiency of the nanocomposite catalysts under different conditions.