Rapid visible light-driven photocatalytic degradation using Ce-doped ZnO nanocatalysts

Abstract

In this work, we have reported the synthesis of Ce-doped ZnO nanostructures with different doping concentrations using simple co-precipitation method. The prepared samples were thoroughly characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDS), Brunauer Emmett Teller (BET), UV–Visible and photoluminescence (PL) spectroscopy. This study was conducted to investigate the effect of the doping concentration of cerium on the structural, morphological, optical, and photocatalytic properties of ZnO. The XRD pattern of synthesized materials displayed wurtzite ZnO structure. FESEM images show the formation of nanobars and nanohexanes along with agglomeration on the change in the doping concentration of Ce3+. The mesoporous nature of nanostructures is confirmed by BET. The incorporation of Ce3+ in ZnO significantly led to the redshift in the band gap in absorption spectra from 3.17 eV to 2.72 eV. The deconvoluted PL spectra revealed that the Ce doping enhances the emission in the blue region due to the transitions between 2D3/2→2Fi/2 energy levels. The Zn0.94Ce0.06O sample exhibited 9.1 times faster photocatalytic activity than the undoped ZnO, under visible light irradiation in 60 min for Methylene blue (MB) dye. The improvement in photocatalytic activity originates from the enhancement in the PL intensity. This is also in good agreement with the increase in the BET surface area for Ce-doped ZnO as compared to undoped ZnO. Thus, Ce-doping enhances the degradation rate, which makes ZnO a potential photocatalyst for the removal of organic pollutants present in water.