Monash University researchers and scientists from the University of Davis in California as well as the Australian Synhchrotron have come up with a method for producing hydrogen from water using manganese and sunlight.
The way it works is the manganese acts as a catalyst as it cycles between two oxidation states. Voltage is used to oxidize the manganese-II state into a manganese-IV state in birnessite. Sunlight then returns it back to a manganese-II state and the process splits water atoms.
When the water is split, it forms a molecule of O2 (oxygen) and four hydrogen nuclei (protons, positively charged) and four electrons. The protons and electrons then combine to form two molecules of H2 (hydrogen). So, the formula is H2O x 2 = H2 + H2 + O2.
The sunlight does two things in this hydrogen producing process. First, it produces the electricity to provide the M-IV and then it provides the return process to M-II so the whole thing can be re-done. The manganese suffers little degradation in the process, making the whole setup infinitely renewable with only sunlight as the input.
You can get more details from Monash University at this link.