Structural, Morphological, and Optical Properties of Cu‐ and Mo‐Doped BiVO ₄ Nanoparticles for Photocatalytic Applications

BiVO ₄ is a narrow‐bandgap semiconductor with excellent chemical stability and promising photocatalytic activity. In this study, pristine BiVO ₄ (BVO), Cu‐doped BiVO ₄ (BVO:Cu), and Mo‐doped BiVO ₄ (BVO:Mo) nanoparticles were synthesized via the sol–gel method, and their structural, optical, morphological, and electronic properties were investigated. The phase of the prepared nanoparticles was identified as a monoclinic scheelite structure using XRD and Raman spectroscopy. XRD results revealed that the crystallite sizes of BVO, BVO: Mo, and BVO: Cu are 25.83, 29.87, and 34.91 nm. Density functional theory studies were carried out to understand the theoretical electronic properties of the pristine BiVO ₄ (BVO). Furthermore, the optical bandgap of the prepared nanoparticles varied from 2.38 to 2.44 eV. Field emission scanning electron microscopy revealed a morphological transformation from irregular spherical particles to rod‐like structures following Cu and Mo doping. Notably, doping significantly enhanced the photocatalytic degradation of methylene blue under visible‐light irradiation. Cu‐doped BiVO ₄ exhibited the highest degradation efficiency of 94.35%, following pseudo‐first‐order kinetics, with the highest apparent reaction rate constant ( k _app  = 0.0567 min ⁻¹ ) alongside excellent reproducibility. These results demonstrate the potential of Cu‐doped BiVO ₄ as an efficient visible‐light photocatalyst.