In the search for alternatives to oil-based fuels, one of the most promising, and challenging, strategies involves splitting water. Researchers have for decades made strides in using sunlight to split water molecules into oxygen and hydrogen, wherein the resulting hydrogen gas can be used as stored fuel. But the method is still too expensive. Materials called catalysts are needed to run the reaction, and the catalyst that works best, platinum, is rare and pricey. The hunt is on for good catalysts made of Earth-abundant, inexpensive materials.