α-Fe2O3 as a versatile and efficient oxygen atom transfer catalyst in combination with H2O as the oxygen source

Haematite (α-Fe2O3) has been extensively investigated as a photoanode in photoelectrochemical water oxidation, but the product O2 has a low economic value. Here we expand its applications to the production of value-added chemicals and report its ability to act as a versatile and efficient oxygen atom transfer catalyst under visible-light irradiation. A variety of organic compounds and inorganic anions were successfully oxidized to the corresponding monooxygenation products with high selectivity and Faradaic efficiency by using water as the sole oxygen source. Photoexcited holes generate iron–oxo species (FeIV=O) on α-Fe2O3 surfaces and the process of oxygen-atom transfer is proposed to proceed via a concerted two-hole transfer pathway that involves the transfer of oxygen atoms from the surface FeIV=O to the substrates. The present study proves α-Fe2O3 is an excellent all-inorganic heterogeneous catalyst to drive oxygen atom transfer reactions, and this strategy has significant potential for the synthesis of fine and high-value-added chemicals.