Multifunctional ZnO/CeO2 nanocomposites for Photoinduced dye degradation and Antibacterial activities.

The ZnO/CeO₂ nanocomposites (Zn_1−xCe_xO₂) were fabricated for different concentrations with x = 0(ZC-1), 0.05(ZC-2), 0.1(ZC-3) and 0.3(ZC-4) via the hydrothermal method. We observed a decrease in particle size by an increase in the concentration of CeO₂ to ZnO. To ensure this Transmission Electron Microscopy (TEM) analysis has been done and the obtained particles size around 42 nm, 26 nm, 22 nm, and 12 nm for ZC-1, ZC-2, ZC-3, and ZC-4 respectively. The purity and chemical composition were investigated by Energy Dispersive X-ray Analysis (EDX) & X-ray Photoelectron Spectroscopy (XPS) analysis. For the first time, the synthesized ZnO/CeO₂ nanocomposites were used as photocatalysts for photocatalytic degradation of the dye neutral red. Initially, the degradation efficiency (ɳ) of ZnO nano catalyst was 45.35%, as we increase the CeO₂ concentration the efficiency of the dye degradation increased appreciably to 56.86%. This is because of more occupancy of surface defects by smaller size particles. Furthermore, the synthesized nanocomposites were studied for their antibacterial activity. Due to the doping of CeO₂, we observed eventually an increase in the zone of inhibition from 12 mm to 19 mm for gram-negative bacteria. We obtained good results for gram-negative bacteria for the higher concentration of the CeO₂ than gram-positive. So, the synthesized Nanocomposites are effective for photocatalytic as well as antibacterial applications. Highlights: ZnO/CeO₂ nanocomposites were synthesized by a simple hydrothermal method for different concentrations. Optical and physicochemical properties were investigated thoroughly. For the first time, photo-induced degradation is explained by the effect of particles size over neutral red. The effect of surface morphology and size of NPs examined for antibacterial activities. [ABSTRACT FROM AUTHOR]