Previously, I talk about practical applications of hydrogen, but in this post, I would like to present you a very new phenomenon, which is still at research stadium: the use of photocatàlisis to produce hydrogen!
The principal is a mix between fuel cells and solar panels: A silicon layer is immerged into water. The system is lighted by the sun, and as silicon react in solar panels, its reaction with the photons creates electron/halls pairs, and so electricity. This electricity is then used to make oxydo-reduction reactions with water, and so to produce gazes of hydrogen.
Let’s see the two different reactions:
- First step : 2H2O –> 4H+ + O2 + 4e–
- The 4H+ moves in water to the other side of the cell before the second step :
- 2nd step : 4H+ + 4e– –> 2H2
In this way, we can collect on a side O2 gaz and on the other side of the cell the H2 gaz. This is a fabulous way to produce hydrogen using directly sun energy isn’t it ?
The Nocera laboratory succeeded in producing the equivalent of 100W of hydrogen with only 1L of water. If this technique reveals to be useful, it would be convenient to use it everywhere, without centralising it in big power plants, and could use sea water, wich means : doesn’t need precious resources.