Barium titanate photocatalysts with silver–manganese dual cocatalyst for carbon dioxide reduction with water.

Titanate photocatalysts with suitable cocatalysts are promising candidates for photocatalytic CO₂ reduction, with the use of water as an electron donor. Here, several barium titanates with various compositions were examined, and BaTi₄O₉ (BT4) was found to be the best photocatalyst with the assistance of an Ag cocatalyst for photocatalytic CO₂ reduction to form CO. The photocatalytic activity was further enhanced by the use of MnO_x as an additional cocatalyst to construct an Ag-MnO_x/BT4 photocatalyst, where Ag and MnO_x were selectively deposited at different facets on BT4 crystal and functioned as active sites for CO₂ reduction and water oxidation, respectively. As for the oxidative products from water, molecular oxygen (O₂) and hydrogen peroxide (H₂O₂) were obtained. [ABSTRACT FROM AUTHOR]