Hydrogen will play a key role in reducing our dependence on fossil fuels. It can be sustainably produced by using solar energy to split water molecules. The resulting clean energy can be stored, used to fuel cars or converted into electricity on demand. But making it reliably on a large scale and at an affordable cost is a challenge for researchers. Efficient solar hydrogen production requires rare and expensive materials—for both the solar cells and the catalyst—in order to collect energy and then convert it.
* This article was originally published here