Photocatalytic reduction of carbon dioxide to formaldehyde was investigated on four semiconductor photocatalysts (FeS, FeS/FeS2, NiO and TiO2). The reaction was carried out in continues flow of CO2 gas bubbled into the reactor. Semiconductor photocatalysts were characterized by X-Ray diffraction (XRD) and Diffuse Reflectance Spectroscopic (DRS) methods. Sulfide ion was used as hole scavenger. The […]