When a plant leaf absorbs sunlight and directly converts it into energy it is known as photosynthesis. The invention that comes closest to photosynthesis is a solar cell that is able to convert only 6% of the total sunlight. Artificial photosynthesis aims to recreate the process of photosynthesis to produce highly efficient energy in many applicable forms.
Plants split water molecules into hydrogen and oxygen. The oxygen is released in the atmosphere. The hydrogen is used to convert the carbon dioxide in the air into carbon-based organic molecules which act as food for the plant. The main idea behind artificial photosynthesis is to split the molecules and use the hydrogen molecule to replace gasoline or other non-renewable sources of energy.
The basic concept is to create sunlight harvesting systems which will be able to capture solar photons. These photons will be able to oxidize water and eventually form a liquid hydrocarbon such as methanol. Researchers have identified nano-crystals of cobalt oxide that can effectively split water molecules. One of the main reasons that cobalt oxide is being used is because it is abundantly available in nature in comparison to its alternative, iridium oxide. Cobalt oxide also has wide commercial use. However, the next step of integrating the carbon dioxide reduction process with an artificial leaf system needs to be developed.
The main benefit of artificial photosynthesis is to produce a hydrogen fuel that will be energy efficient and carbon neutral. It will be a renewable source of energy which can be used for transportation. It will not add any green house gases into the atmosphere. On the other hand, artificial photosynthesis may actually help to mop up large amounts of carbon dioxide from the air to produce liquid fuels.