Unlocking Copper-Free\nInterfacial Asymmetric C–C\nCoupling for Ethylene Photosynthesis from CO<sub>2</sub> and H<sub>2</sub>O

Solar-driven carbon dioxide (CO<sub>2</sub>) reduction\ninto C<sub>2+</sub> products such as ethylene represents an enticing\nroute toward\nachieving carbon neutrality. However, due to sluggish electron transfer\nand intricate C–C coupling, it remains challenging to achieve\nhighly efficient and selective ethylene production from CO<sub>2</sub> and H<sub>2</sub>O beyond capitalizing on Cu-based catalysts. Herein,\nwe report a judicious design to attain asymmetric C–C coupling\nthrough interfacial defect-rendered tandem catalytic centers within\na sulfur-vacancy-rich MoS<sub><i>x</i></sub>/Fe<sub>2</sub>O<sub>3</sub> photocatalyst sheet, enabling a robust CO<sub>2</sub> photoreduction to ethylene without the need for copper, noble metals,\nand sacrificial agents. Specifically, interfacial S vacancies induce\nadjacent under-coordinated S atoms to form Fe–S bonds as a\nrapid electron-transfer pathway for yielding a Z-scheme band alignment.\nMoreover, these S vacancies further modulate the strong coupling interaction\nto generate a nitrogenase-analogous Mo–Fe heteronuclear unit\nand induce the upward shift of the d-band center. This bioinspired\ninterface structure effectively suppresses electrostatic repulsion\nbetween neighboring *CO and *COH intermediates via d-p hybridization,\nultimately facilitating an asymmetric C–C coupling to achieve\na remarkable solar-to-chemical efficiency of 0.565% with a superior\nselectivity of 84.9% for ethylene production. Further strengthened\nby MoS<sub><i>x</i></sub>/WO<sub>3</sub>, our design unveils\na promising platform for optimizing interfacial electron transfer\nand offers a new option for C<sub>2+</sub> synthesis from CO<sub>2</sub> and H<sub>2</sub>O using copper-free and noble metal-free catalysts.