Scientists are looking for cheaper and more efficient ways to produce hydrogen and oxygen through water splitting. They have been working on developing new materials made of single atoms and clusters of metals like iron, cobalt, nickel, and molybdenum. These materials show promising results in catalyzing the reactions needed for water splitting. By tweaking the shape, defects, and composition of these materials, researchers are making progress in creating better catalysts for this important process. The goal is to find alternatives to expensive and scarce materials like platinum and iridium oxide/ruthenium oxide.