1.  Instead of splitting hydrogen sulphide, they developed the ability to split water by first trapping solar energy in green pigments.

2.  The green-pigmented organisms that could split water inherited the Earth.

3.  This is then used to split water into hydrogen and oxygen, creating a fuel which is portable, cheap and very clean.

4.  Where would you get the energy to actually split the water into hydrogen and oxygen?

5.  Instead, Nocera has focused on finding a way to use light to split water into its components, hydrogen and oxygen.

6.  Photocatalysts that can split water have been around for decades.

7.  Splitting water is very inefficient and it would take a lot of research to turn it into a practical means of generating energy, he explains.

8.  The trouble is, the only way to make hydrogen at the moment is to split water with electrical energy from polluting power stations.