Photoassisted Carbon Dioxide Reduction to Organic Compounds Using Rare Earth Doped Barium Titanate and Lithium Niobate as Photoactive Agents

The effect of rare earth dopants on the large bandgap semiconductors, barium titanate and lithium niobate, in the photoassisted reduction of carbon dioxide was studied in aqueous suspensions, by illumination with high pressure mercury lamps. The yields of the reduction products formic acid and formaldehyde was enhanced by the presence of low concentrations of the oxides of europium, neodymium, samarium and cerium in the above semiconductors. The optical properties of the materials were studied by diffuse reflectance spectroscopy.