Defect dipoles and stable dielectric properties improve Nb-doped Ba_0.7Sr_0.3TiO₃ photocatalytic H₂ evolution activity

Abstract

To enhance the photocatalytic hydrogen evolution reaction (HER) activity and stability of barium strontium titanate (Ba0.7Sr0.3TiO3, BST), niobium (Nb5+) donor doped BST (Ba0.7Sr0.3Ti1-xNbxO3) photocatalysts were synthesized via the sol gel...

Visible-light-driven oxygen evolution by a BaTiO3 based ferroelectric photocatalyst via water splitting

“…13 So far, BTO is utilized primarily for the HER in the presence of external bias and ultraviolet light as the photon source. 14,15 However, the valence band of BTO is situated at a potential sufficiently high to facilitate the oxidation of water and the generation of oxygen. 16 Therefore, this material holds promise as an OER photocatalyst for producing oxygen concurrently with hydrogen.…”

“…21 As a photocatalyst for water-splitting, BTO has a significant drawback of rapid electron–hole recombination during photocatalytic reactions. 22 To address the challenges outlined and design an effective photocatalyst for the process of photocatalytic water-splitting, it is necessary to reduce the band gap energy of BTO while preserving its inherent ferroelectric properties so that its polarization can contribute to charge separation during reactions. It is reported that the Jahn–Teller charge neutral dipole doping strategy can achieve lower band gap energy and at the same time it can retain its spontaneous ferroelectricity.…”