title: BiFeO3/TiO2 nanotube arrays composite electrode: construction, characterization, and enhanced photoelectrochemical properties.
abstract: This work aims at the exploration of nanostructured ferroelectric-material-modified semiconductor electrodes for enhanced photo-induced activity. A well-aligned BiFeO3/TiO2-nanotubes (NTs) array with visible-light activity was successfully synthesized on a titanium sheet by combining anodization and an ultrasonic-immersion method followed by annealing. The structural and optical properties of the TiO2-NTs and the composite BiFeO3/TiO2-NTs were comparatively characterized. The composite BiFeO3/TiO2-NTs grown on a Ti sheet and used as an electrode exhibited a stronger absorption in the visible region and a much higher photoconversion efficiency than the pure TiO2-NTs/Ti electrode. Electrochemical impedance investigation attested to a significant improvement of the interfacial electron-transfer kinetics with enhanced separation of electron-hole pairs. The as-prepared composite electrode showed a high efficiency for photoelectrocatalytic degradation towards rhodamine B under visible-light irradiation (λ > 400 nm). The enhanced photoelectrocatalytic activity of the composite electrode could be attributed to the synergistic effect between the lowered electron-hole recombination rate by the applied bias and the wider spectral response promoted by the BiFeO3 component.
authors.affiliation: State Key Laboratory of Fine Chemicals, Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), School of Environmental Science and Technology, Dalian University of Technology , Dalian 116024, China.
authors.forename: Ashu
authors.initials: A
authors.lastname: Zhu
authors.forename: Qidong
authors.initials: Q
authors.lastname: Zhao
authors.forename: Xinyong
authors.initials: X
authors.lastname: Li
authors.forename: Yong
authors.initials: Y
authors.lastname: Shi