Optical properties and visible light-driven photocatalytic activity of Bi₁₁VO₁₉ nanoparticles with δ-Bi₂O₃-structure

Highlights: • A visible-light-driven photocatalyst Bi₁₁VO₁₉ was developed by a Pechini method. • Bi₁₁VO₁₉ shows an efficient optical absorption with a narrowed band-gap 2.23 eV. • Bi₁₁VO₁₉ nanoparticles show a photocatalytic activity on MB photo-degradation. • The lattices show distorted Bi³⁺, big polarizing fields and high openness degree. • The photocatalytic activity of Bi₁₁VO₁₉ is related to its structural specialties. - Abstract: The δ-Bi₂O₃-structural Bi₁₁VO₁₉ nanoparticles with the average size of ∼70 nm were fabricated through the Pechini method for a possible photocatalytic application. The crystal structure was investigated by X-ray powder diffraction (XRD) and the structural refinement. The as-synthesized sample was also characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray spectroscopy (EDX), UV–vis spectroscopy and photoluminescence measurements. The experimental results demonstrate that Bi₁₁VO₁₉ nanoparticles have an efficient visible light absorption with band-gap energy of 2.23 eV. The photocatalytic activity was evaluated by the photodegradation of the methylene blue (MB) under visible light irradiation (λ > 420 nm) as a function of time. All the results indicate that Bi₁₁VO₁₉ could be a potential photocatalyst driven by visible-light. The effective photocatalytic activity was discussed on the base of the crystal structure characteristic