Iron ion enables photocatalytic hydrogen evolution from methanol.

Global demand for hydrogen gas is expected to increase as efforts toward carbon neutrality intensify. Hydrogen emits no carbon dioxide during use and is regarded as a promising clean energy carrier, with technologies such as fuel cells being actively developed. However, most hydrogen is currently produced from fossil resources such as natural gas and oil, creating an urgent need for sustainable production methods. Although hydrogen can be produced from water or renewable feedstocks including alcohols, sewage sludge, and waste plastics, the high cost of these technologies remains a major barrier to practical implementation. Here we report a simple photocatalytic system for hydrogen production via alcohol dehydrogenation using iron, the most abundant and inexpensive metal on Earth. Driven by light energy, this ligand-free catalytic system represents a remarkably simple platform for sustainable hydrogen generation.