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 platform is established over niobium oxide (Nb2O5) nanowires for selective aerobic oxidation of alcohols. Mechanistic investigation reveals that the formation of visible light harvesting alcohol-Nb2O5 surface complexes initiates the selective oxidation of aromatic alcohol with molecular oxygen (O2). Notably, the oxygen isotope labeling study provides compelling evidence that O2 acts exclusively as an acceptor of hydrogen rather than being transferred into the final oxidation product aldehydes. This work offers fundamental insights into the essential role of O2 in photocatalytic selective chemical transformations.