Fabrication of ZnO/CuO Hybrid Nanocomposite for Photocatalytic Degradation of Brilliant Cresyl Blue (BCB) Dye in Aqueous Solutions

Here in the present study, we report the synthesis of ZnO nanoparticles, ZnO/CuO(3%), ZnO/CuO(5%), and ZnO/CuO(10%) nanocomposites using a simple precipitation method with the variation of CuO content and the activities of the prepared samples were investigated for degradation of Brilliant Cresyl Blue (BCB) dye under visible light conditions in aqueous solutions. The structural, morphology, optical and compositional characteristics of fabricated samples were characterized by using Fourier Transform Infra-Red (FT-IR) Spectroscopy, Field Emission Scanning Electron Microscopy combine electron dispersive spectroscopy (FESEM-EDS) and UV-vis spectroscopy. FESEM images show that ZnO nanoparticles have a polygon-like shape structure while ZnO/CuO have polygon and sheet shape structures. XRD patterns reflect the high crystallinity and purity of samples. The optical band gap values determined from the optical absorption method indicate that band gap energy decreased with the increase of CuO content in ZnO. The catalytic efficiency of the ZnO/CuO hybrid nanocomposite was observed to be higher than the ZnO nanoparticles under similar reaction conditions, 97.30% of Brilliant Cresyl Blue (BCB) dye was degraded after 100 min of irradiation of visible light radiation using the ZnO/CuO(5%) hybrid nanocomposite. The higher efficiency of ZnO/CuO compare to ZnO may be due to increased surface area and decreased bandgap energy. The kinetic study of photocatalytic degradation displayed that hybrid ZnO/CuO degraded dye with high rate constant k (34.88x10^-3 min^ -1) in comparison to ZnO (k, 7.00x10^-3 min^-1). Reaction conditions optimization of the photodegradation process was attained by the variation in reaction factors such as pH, dye concentration, catalyst amount, and reaction time.