Bismuth Oxybromide with Reasonable Photocatalytic Reduction Activity under Visible Light

The original bismuth-based oxyhalide, known as the Sillén family, is an important photocatalyst due to its high photocatalytic oxidation activity. Here, we report a bismuth-based photocatalyst, Bi 24 O 31 Br 10, with reasonable reduction activity. The photoreduction capability of Bi 24 O 31 Br 10 in H 2 evolution from water reduction is 133.9 μmol after 40 h under visible light irradiation. Bi 24 O 31 Br 10 presents the highest activity among Bi 2 O 3, BiOBr, and Bi 24 O 31 Br 10 in photocatalytic reduction of the Cr (VI) test, and Cr (VI) ions are totally removed in 40 min. The Mott–Schottky test shows the bottom of the conduction band fits the electric potential requirements for splitting water to H 2 . First-principles calculations indicate the conduction band of Bi 24 O 31 Br 10 mainly consists of hybridized Bi 6p and Br 4s orbitals, which may contribute to the uplifting of the conduction band.