Solar-Driven Glucose Isomerization into Fructose via Transient Lewis Acid–Base Active Sites

The selective glucose isomerization to fructose is an essential step for various industrial biofuels and biochemicals production. However, current biological and acid–base catalysis processes still suffer from poor glucose conversion and low fructose selectivity. Here, we demonstrate an effective strategy for fast sunlight-driven glucose isomerization with over 60% fructose selectivity. This process is realized by a rationally designed crystalline carbon nitride (CN) prepared via the combination of supramolecular preorganization and the molten-salt method. The high in-plane crystallinity and extended π-conjugation significantly enhance visible-light absorption and charge separation. We show that the surface nitrogen vacancies and cyano groups induce rearrangement of the electron cloud under light irradiation and introduce the transient Lewis acid–base active sites, which result in the activation of the oxygen atoms (O1 and O2) of glucose and the deprotonation of O2–H to selectively produce fructose. This work provides a protocol for biofuels/chemicals production via a photocatalysis process.