Enhanced interface coupling accelerates charge transfer of a MoO _{2− <i>x</i>} /Bi ₂ MoO ₆ Schottky junction for CO ₂ photoreduction to CH ₄

Abstract Artificial photosynthesis, converting CO 2 and H 2 O into solar fuels, is considered as a strategic pathway to alleviate the greenhouse effect and the energy crisis. Nonetheless, in many heterojunction‐based artificial photosynthetic systems, the CH 4 productivity is significantly limited by poor carrier transport, narrow spectral light absorption, and lacking suitable active sites for the eight‐electron reaction. Herein, a MoO 2− x /Bi 2 MoO 6 (MO/BWO) Schottky junction with a strong interfacial coupling effect was fabricated by a two‐step hydrothermal strategy. The optimized MO/BMO Schottky junction delivered a CO 2 ‐to‐CH 4 photoreduction rate of 23.3 μmol g −1 with 90.7% selectivity. In situ X‐ray photoelectron spectroscopy and theoretical calculation demonstrated that BMO interacted with MO to produce a strong electron coupling effect and form a Schottky junction, which promoted the facilitated the directional migration of photogenerated electrons from BMO to MO with prolonging average photogenerated charge lifetime from 26.6 to 48.7 ps, but also effectively suppressed electron backflow through the Schottky barrier. Moreover, the coupling of MO with BMO significantly reduced the energy barrier of the rate‐determining step. This work delves into the role of non‐precious metal‐based Schottky junction design in enhancing photocatalytic CO 2 reduction performance, providing new insights into co‐catalyst as active sites for CH 4 generation in the CO 2 photoreduction process.