Photohydrogen

Photohydrogen is hydrogen produced with the help of artificial or natural light (Photolysis). This is how the leaf of a tree splits water molecules into hydrogen (to make carbohydrates) and oxygen (released into the air for us to breathe). Photohydrogen may also be produced by the photodissociation of water by ultraviolet light. Photohydrogen is sometimes discussed in the context of obtaining renewable energy from sunlight, by using microscopic organisms such as bacteria or algae.