Visible light-initiated selective aerobic oxidation of alcohols over niobium oxide nanowires: an oxygen isotope labeling study

Abstract

As a cornerstone chemical transformation, the oxidation of alcohols to aldehydes often relies on environmentally detrimental oxidants. Here, a photocatalytic system is established over niobium oxide (Nb₂O₅) nanowires for visible light-initiated selective aerobic oxidation of alcohols. Mechanistic investigation reveals that the formation of a visible light harvesting alcohol–Nb₂O₅ surface complex initiates the selective oxidation of aromatic alcohols with molecular oxygen (O₂). Notably, the oxygen isotope labeling study provides compelling evidence that O₂ acts exclusively as a hydrogen acceptor rather than being transferred into the final oxidation product aromatic aldehydes. This work offers fundamental insights into the essential role of O₂ in photocatalytic selective chemical transformations.