Stanford University scientists have developed a low coat, corrosion free silicon-based water splitter comprising a silicon semiconductor coated with an ultrathin layer of nickel. The researchers believe that this could pave the way for large-scale production of clean hydrogen fuel from sunlight.
In a water splitter, two semiconducting electrodes are connected and placed in water. The electrodes absorb light and use the energy to split the water into oxygen and hydrogen. The oxygen is released into the atmosphere and the hydrogen is stored as fuel.
Finding a cheap way to split water has been a major challenge.
Silicon would be an ideal, low cost material to use in a water splitter except that, as soon as the water splitting process starts, a submerged silicon electrode corrodes.
When the Stanford researchers coated the silicon with a 2 nanometre thick layer of nickel, the water splitting process lasted for 24 hours without any corrosion. Adding lithium to the electrolyte solution increased this to more than three days.
The researchers believe that further development will yield a corrosion free water splitter made from cheap, abundant materials.