Boosting Photocatalytic Activity in Rhodamine B Degradation Using Cu-Doped ZnO Nanoflakes

The present investigation examined how substituting some Cu²⁺ ions for Zn²⁺ ions could increase zinc oxide (ZnO) photocatalytic activity toward the reduction of Rhodamine B. Phase composition, the presence of functional groups, optical properties, emission spectra, and surface morphology of ZnO nanoflakes (NFs) were evaluated using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), UV–visible spectroscopy (UV–vis), photoluminescence (PL) spectrophotometer, and scanning electron microscopy (SEM). To investigate the photocatalytic capabilities of Cu-doped ZnO NFs driven by visible light/sunlight, Rhodamine B dyes were photocatalytically degraded in water using UV–visible absorption spectroscopy. Using Williamson-Hall analysis of the XRD data, it was discovered that the internal strain of the Cu-doped ZnO NFs was altered. UV–vis absorption showed that the energy gap of the semiconducting ZnO NFs shrank when Cu was substituted. FT-IR studies revealed that the surface of the Cu-doped ZnO NFs contained greater amounts of reactive oxidizing species. PL studies revealed that the ZnO NFs’ surface defects were being caused by the Cu substitution. According to SEM research, more surface fault NFs formed when the concentration of Cu increased. The photocatalytic activity was enhanced by the production of these NFs. The UV–vis absorption spectra showed that Cu-doped ZnO NFs were more effective than pure ZnO at degrading the rhodamine B dye (RhB). Finally, it was shown that replacing Zn²⁺ ions with Cu²⁺ ions improved the photodegradation of the rhodamine B dye. According to this study, Cu-doped ZnO NFs are an excellent choice for wastewater treatment.