Facile Synthesis of Single-Crystalline Ag2V4O11 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 Ag2V4O11 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 Ag2V4O11 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.