Abstract: A device for the photosynthetic reduction of carbon dioxide and water by sunlight to formic acid, formaldehyde and methanol in the presence of semiconducting photoactive materials. Using preferred compositions of photoactive materials, selected from oxides and sulfides of copper, iron, molybdenum, ruthenium, lead, titanium, and from mixtures of any of these, and from barium titanate, calcium titanate, and strontium titanate, this photochemical solar collector also achieves photothermal energy conversion, thus providing the energy required for continuous distillation and recovery of the above organic materials produced.