Visible-light-driven BaBiO3 perovskite photocatalysts: Effect of physicochemical properties on the photoactivity towards water splitting and the removal of rhodamine B from aqueous systems

Abstract

In this work, visible-active BaBiO3 perovskite photocatalysts were prepared by solid state and hydrothermal methods. The physicochemical characterization of the materials was carried out by XRD, SEM, UV–vis, PL and EIS analysis. It was found that the materials exhibit a base centered monoclinic structure with morphology of dense irregular particles and an absorption edge near to 620 nm (∼2 eV) in the visible region. In the photocatalytic tests, BaBiO3 efficiently performed the water splitting reaction and the degradation of rhodamine B (RhB) under visible light using a solar simulator with a Xe- lamp, obtaining attractive yields in both processes (61 μmol g−1 h−1 of H2 evolution and 80% of RhB degradation), which are higher than the reported in previous works for BaBiO3 and competitive with the activity of TiO2 under UV light. The dependence of the catalytic activity in the photoinduced processes from the physicochemical properties of BaBiO3 powders prepared by solid state and the hydrothermal route is studied. According to the results, the crystallinity played the main role in determining the photocatalytic performance of the materials. BaBiO3 synthesized by solid state reaction exhibited the highest crystallinity and presented the best performance compared to the materials synthesized by hydrothermal method. Also, BaBiO3 obtained by solid-state shows the lower resistance for the charge transfer. In summary, the suitable photoabsorption, crystalline structure, and electronic properties of BaBiO3 powders determined their effective application and high activity in the water splitting and degradation of rhodamine B processes. In addition, the potential properties of this compound as a visible-light-driven photocatalyst favored its application in both processes.