Nitric acid is among the most important industrial chemicals, yet its large-scale production consumes vast amounts of fossil energy. In nature, nitrifying bacteria oxidize ammonia (NH3) to nitrate (NO 3 − ) via two separate microorganisms—ammonia-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB). Here, we report a conceptual synthetic nitrifying enzyme that mimics this biological process under mild conditions but employs a single photocatalyst rather than multiple catalysts as used in both nature and industry. The synthetic enzyme demonstrates high selectivity (99%) for NO 3 − formation and operates at room temperature and 1 atm pressure. This simplified design provides a biomimetic yet efficient route for ammonia oxidation and may inspire future development of sustainable synthetic nitrification systems for industrial applications.
