Relaxor ferroelectric and photocatalytic properties of BaBi₄Ti₄O₁₅

Aurivillius phase BaBi4Ti4O15 micro-sized powders were produced by solid-state reaction and their photocatalytic properties were reported for the first time. X-ray diffraction revealed the polar orthorhombic structure. BaBi4Ti4O15 ceramics exhibited diffuse phase transition at ∼ 410°C. The freezing temperature of 274°C was obtained by fitting the Vogel–Fulcher law. The distinct ferroelectric domain switching current peaks in current – electric field (I-E) loop and piezoelectric coefficient d33 value of 7.0 ± 0.1 pC/N at room temperature further demonstrated relaxor ferroelectric behaviour of BaBi4Ti4O15. UV-vis absorption spectra indicated that BaBi4Ti4O15 had a direct band gap of 3.2 eV. The photocatalytic study showed 15% degradation of Rhodamine B (RhB) solution by BaBi4Ti4O15 powders after 3.5 h UV-vis irradiation. The RhB degradation rate was further enhanced by depositing Ag nanoparticles on the BaBi4Ti4O15 powders surface. This work suggested that the relaxor ferroelectric BaBi4Ti4O15 is promising for photocatalytic applications.