"Bill Gates has said that to solve our energy problems, someday we need to do what photosynthesis does, and that someday we might be able to do it even more efficiently than plants...That someday has arrived" - David Nocera, Harvard University
David Nocera & his colleague Pamela Silver, professors of energy science, biochemistry & systems biology (respectively) have co-created a system that combines H20 splitting solar energy and hydrogen-eating bacteria to essentially produce liquid fuel from sunlight, carbon dioxide and water.
The "Bionic Leaf" (version 2.0) is a cutting edge hybrid approach to artificial photosynthesis that can convert solar energy to biomass at an efficiency rate of about 10% using pure CO2 and 3-4% using air, which believe it or not, far surpasses "real" photosynthesis. ("Real" or plant based photosynthesis generates about 1% return of carbohydrates from solar energy in efficient plants)
Generally speaking, artificial photosynthesis seeks to use solar energy, water, and carbon dioxide to produce energy dense liquid fuels in the same way that plants use the same elements to produce energy. The process has the potential to be carbon neutral, which is a huge upside, environmentally speaking. Pretty exciting stuff!
I did an article for Oil & Energy Magazine this month that deals with the Bionic Leaf & Artificial Photosynthesis, if you want a little more on the chemistry and details involved you can read that article here: "Bionic Leaf Turns Sunshine, Water and CO2 into Liquid Fuel"