Facile synthesis of single-crystalline Ag₂V₄O ₁₁ nanotube material as a novel visible-light-sensitive photocatalyst

Ag₂V₄O₁₁ nanotubes were synthesized by means of a facile surfactant-assisted hydrothermal process and developed as a novel visible-light-sensitive photocatalyst for 2-propanol (IPA) decomposition. The Ag₂V₄O₁₁ nanotubes were single-crystalline and showed a uniform size with a diameter of about 10 nm in width and micrometer-sized length. The material can absorb a wide range of light irradiation up to 600 nm. The band gap of Ag₂V₄O ₁₁ was determined to be 2.0 eV according to the diffuse reflectance spectrum of the sample. The electronic structures and band edge positions of Ag₂V₄O₁₁ were theoretically calculated on the basis of density functional theory and the constituent atom's Mulliken electronegativity, respectively. It was revealed that the valence band consisted of Ag 4d and O 2p orbitals, while the conduction band was constructed by V 3d and Ag 5s5p orbitals. Compared with commercial N-TiO₂, the Ag ₂V₄O₁₁ nanotube catalyst exhibited much higher photocatalytic activity for IPA degradation under visible-light irradiation. It was possibly ascribed to the narrow band gap, highly mobile charge carriers, and tubular structure.