Highly efficient natural-sunlight-driven photodegradation of organic dyes with combustion derived Ce-doped CuO nanoparticles

Abstract

CuO nanoparticles doped with various concentrations of Ce (2, 4, and 6 mol%) were synthesized by using the solution combustion method. The as-synthesized nanoparticles were characterized by X-ray diffractometer (XRD), fourier transforms infrared spectroscopy (FTIR), field emission scanning electron microscope (FESEM) and energy-dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), UV–Vis–NIR spectroscopy and photoluminescence (PL) spectroscopy. XRD analysis revealed that the physical parameters such as crystallite size, strain, lattice parameters, dislocation density and stacking fault of CuO nanoparticles were affected after the doping of Ce. FTIR analysis showed that Ce dopants affected the average force constant and the average bond length of CuO nanoparticles. UV–Vis–NIR spectrum analysis showed an enhanced absorption spectrum and narrowed down of the bandgap of CuO from 1.39 eV to 1.28 eV with Ce doping and resulted in increasing refractive index and optical conductivity. PL emission spectra showed a decrease in intensities after doping with Ce by trapping photoinduced electron of CuO by Ce dopants. The photocatalytic activities of the as-synthesized sample were investigated by photocatalytic degradation of organic dyes such as Rhodamine-B (RhB) and Methylene blue (MB), with and without the assistance of H2O2 under solar irradiation. The highest photocatalytic efficiency is obtained with Ce (4 mol%) doped CuO at 95.39% and 87.72% for RhB and MB dyes.