See: http://e.nikkei.com/e/fr/tnks/Nni20110920D2009A09.htm
NAGOYA (Nikkei)--A Toyota Motor Corp. (7203) group research firm said Tuesday that it has developed technology that duplicates how plants make energy, using only sunlight, water and carbon dioxide. Artificial photosynthesis is not new, but Toyota Central R&D Laboratories Inc. says it has found the world's first method that does not require special additives. The reaction uses a metal-coated semiconductor as a photocatalyst and gives off oxygen and formic acid as byproducts. Developing practical uses will likely take some time. The process converts sunlight into energy at an efficiency of 0.04%, making it only about a fifth as good as plants in general, according to senior researcher Tsutomu Kajino. . . .
