Microwave-Assisted Synthesis of Visible Light-Driven BiVO4 Nanoparticles: Effects of Eu3+ Ions on the Luminescent, Structural, and Photocatalytic Properties

The optimization of BiVO4-based structures significantly contributes to the development of a global system towards clean, renewable, and sustainable energies. Enhanced photocatalytic performance has been reported for numerous doped BiVO4 materials. Bi3+-based compounds can be easily doped with rare earth (RE3+) ions due to their equal valence and similar ionic radius. This means that RE3+ ions could be regarded as active co-catalysts and dopants to enhance the photocatalytic activity of BiVO4. In this study, a simple microwave-assisted approach was used for preparing nanostructured Bi1−xEuxVO4 (x = 0, 0.03, 0.06, 0.09, and 0.12) samples. Microwave heating at 170 °C yields a bright yellow powder after 10 min of radiation. The materials are characterized through X-ray diffraction (XRD), transmission electron microscopy (TEM), ultraviolet–visible–near-infrared diffuse reflectance spectroscopy (UV-Vis-NIR DRS), photoluminescence spectroscopy (PL), and micro-Raman techniques. The effects of the different Eu3+ ion concentrations incorporated into the BiVO4 matrix on the formation of the monoclinic scheelite (ms-) or tetragonal zircon-type (tz-) BiVO4 structure, on the photoluminescent intensity, on the decay dynamics of europium emission, and on photocatalytic efficiency in the degradation of Rhodamine B (RhB) were studied in detail. Additionally, microwave chemistry proved to be beneficial in the synthesis of the tz-BiVO4 nanostructure and Eu3+ ion doping, leading to an enhanced luminescent and photocatalytic performance.