There isn't a single molecule that can split hydrogen and oxygen atoms in the sense of breaking the strong covalent bonds that hold them together in a water molecule (H₂O).

However, here's what you need to know:

* Electrolysis: This is a process that uses electricity to split water molecules. In this case, the energy from the electricity is used to break the bonds in water, producing hydrogen gas (H₂) and oxygen gas (O₂).

* Photolysis: This is a process where light energy, particularly ultraviolet light, can break down water molecules. This is a key reaction in photosynthesis.

* Certain enzymes: Some enzymes, like the oxygen-evolving complex (OEC) in plants, can catalyze the splitting of water molecules during photosynthesis.

So, while there's no single molecule that can directly split hydrogen and oxygen atoms, there are chemical processes and biological systems that utilize energy to break these bonds.