Investigation of photocatalytic properties based on Fe and Ce Co-doped ZnO via hydrothermal method and first principles

In this study, Fe and Ce co-doped ZnO (Zn1-2xFexCexO, x = 0, 0.01, 0.03, 0.04) was prepared through hydrothermal synthesis, followed by annealing. The samples were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, UV–vis spectroscopy, and photoluminescence spectroscopy, and the photocatalytic efficiency of the samples on the organic dye, methylene blue, under simulated sunlight was studied. Based on first principles, the influence of doping on the band structure of the samples was studied. The experimental results show that co-doping ratios affect the performance of ZnO. When the doping concentration was 3 at%, the red shift of the UV–vis spectrum of the material was the most obvious, and the PL of the material was inhibited. Compared with pure ZnO, the degradation rate increased from 72.6% to 98.5%. As the doping concentration increased, the photocatalytic performance of the materials began to decrease. Simulations showed that the incorporation of small amounts of Fe and Ce reduced the band gap of ZnO and introduced a shallow donor level in the band gap, effectively inhibiting the recombination of carriers, thereby improving the photocatalytic performance of the material. When the doping ratio was increased from 3% to 4%, the band gap became wider. These results indicate that Fe and Ce co-doped ZnO has potential applications in the photocatalytic degradation of organic pollutants and provides a method for improving photocatalytic performance by inhibiting carrier recombination.