Carbon nanotubes are the crucial chemical ingredient that could make artificial photosynthesis possible, say Chinese researchers.

Artificial photosynthesis could efficiently produce hydrogen that could be used as a clean fuel and also mop up carbon dioxide from the atmosphere.

By covalently bonding a large number of phthalocyanine molecules to a carbon nanotube, they could create a multiple electron system activated by visible light. The extra electrons stored in the nanotubes could be used to convert a chloroplast chemical called NADP into NADPH, which could then reduce carbon dioxide to carbohydrates.