Enlarge Image Transformer. After nanocrystals use sunlight’s energy to split water molecules into oxygen and hydrogen, a nickel catalyst snags electrons from the oxygen and uses them to knit hydrogen molecules together—making hydrogen fuel. Credit: Ted Pawlicki/University of Rochester Technology is always looking for ways to make it easier to be green. Now, researchers in New York state report creating a new long-lived catalyst that uses the energy in sunlight to generate hydrogen gas, a carbon-free fuel. With further improvements, the advance could lead to systems that use sunlight to split water molecules, generating a fuel that can power...