An artificial leaf producing hydrogen and oxygen from the sun

An elegant solution of photo-electrochemical (PEC) production of hydrogen: 

http://www.nature.com/news/2011/110929/full/news.2011.564.html#B1

Even if in 2012, this solution is too expensive (production of 1kg of Hydrogen for 6,5$ instead of 1 to 2$ from fossil fuel):

http://www.nature.com/news/artificial-leaf-faces-economic-hurdle-1.10703