Magnetic-field-dominated spin-driven lattice deformation of 2D FeO/Cu2O composites for CO2 photocatalytic C–C coupling

Spin is an important degree of electronic freedom that can be utilized to design new materials and possibly even construct new matter states. This study demonstrates that the transition of Fe outer electrons from the low-spin state to the high-spin state can be triggered by applying a magnetic field during the deposition of Fe on Cu2O. Magnetic-field-dominated spin rearrangement drives the directional splitting of the Fe d orbital and promotes the interphase oxygen migration of Cu2O to surface reconstruct the Cu clusters attached to the 2D FeO materials. The spin-driven 2D FeO/Cu2O material featured dual active sites, which could realize C–C coupling during the photoreduction of CO2 to ethanol with an outstanding yield and selectivity of as high as 9.69 μmol g−1 h−1 and 60.8%, respectively. Our results demonstrate the important role of spin regulation in the design of photocatalytic materials and open up a new pathway for inorganic synthesis.