Revisiting the BaBiO3 semiconductor photocatalyst: synthesis, characterization, electronic structure, and photocatalytic activity

This article revisits the properties of BaBiO3 examined extensively in last two decades because its electronic as a superconductor and semiconductor photocatalyst. Solid-state syntheses this bismuthate have often involved BaCO3 barium source, which may lead to formation BaBiO3/BaCO3 heterostructures that could an impact on and, more importantly, photocatalytic activity bismuthate. Accordingly, we synthesized by solid-state route avoid use carbonate; it was characterized XRD, SEM, EDX, while elemental mapping composition morphology crystalline thin films with respect structure, optoelectronic, properties. XPS, periodic DFT calculations, electrochemical impedance spectroscopy ascertained electrical properties, Raman DRS spectroscopies assessed relevant optical The determined via degradation phenol aqueous media. Although some results accorded earlier studies, newer structural data bismuthate, together experiments carried out presence selective radical trapping agents, led elucidating mechanistic details processes previous views band structure failed address or clarify. Analytical refinement XRD inferred as-synthesized adopted C2/m symmetry rather than I2/m reported earlier, Tauc plots from spectra yielded bandgap 2.05 eV versus range 1.1–2.25 others; corresponding flatband potentials were 1.61 (EVB) − 0.44 (ECB). somewhat greater well-known Evonik P25 TiO2 photocatalyst under comparable experimental conditions.