Efficient rhodamine B dye photocatalytic degradation in aqueous media using novel ZnO nanomaterials co-doped with Ce and Dy

Abstract

Water pollution caused by dyes and industrial wastewater poses a significant threat to ecosystems. The purification of such pollutants presents a major challenge. Photocatalysis based on semiconductor materials is a potential wastewater treatment process due to its safety and cost-effectiveness. In the present work, Zn1-2xCexDyxO (x = 0.01–0.05) semiconductors were prepared by the sol-gel auto-ignition method. The samples are denoted CDZO1, CDZO3, and CDZO5 for x = 0.01–0.05, respectively. The X-ray diffraction and Raman spectroscopy results revealed the formation of ZnO hexagonal phase wurtzite structure for all synthesized compositions. Different structural properties were determined. It was found that the lattice parameters and the unit cell volume increased, while the crystallite size diminished as x varied from 0.01 to 0.05. Transmission electron microscopy observations confirmed the formation of nanoparticles with the desired chemical compositions. The specific surface area (SSA) values are found to be 39.95 m2/g, 48.62 m2/g, and 51.36 m2/g for CDZO1, CDZO5, and CDZO5 samples, respectively. The reflectance spectra were recorded to examine the optical properties of the different nanoparticles. The values of the optical band gap were 3.221, 3.225, and 3.239 eV for CDZO1, CDZO3, and CDZO5 samples, respectively. In addition, the photocatalytic performance towards RhB dye degradation for the different samples was assessed. It was established that the CDZO3 sample with a moderate SSA value exhibited the superior photocatalytic performance among the other as-prepared samples wherein the percentage of degradation efficiency, and kinetic constant rate attained their maximum values of 98.22 % and 0.0521 min−1, respectively within 75 min. As per the obtained findings, it is evident that the Zn1-2xCexDyxO photocatalyst has prominent potential for use in the degradation of dyes and offers a useful route for impeding the recombination of electron-hole pairs of zinc oxide material.