Abstract
The strategic engineering of an Ohmic junction at the Bi/Bi(2)O(3) (BBO) interface is demonstrated to synergistically enhance photocatalytic CO(2)-to-methanol conversion through precisely modulated charge behavior and interfacial energy alignment. This metallic Bi-semiconductor Bi(2)O(3) Ohmic junction with local surface plasmon resonance effect induces a robust built-in electric field that promotes the unidirectional electron transfer from Bi(2)O(3) to Bi while suppressing charge recombination. Theoretical calculations and experimental evidence reveal that the interfacial Bi sites within the Ohmic junction predominantly facilitate CO(2) adsorption and activation to form *COOH, whereas ensuing protonation steps are favored on metallic Bi sites on BBO Ohmic junction. Furthermore, the Ohmic junction enhances interfacial electron density and strengthens orbital hybridization between Bi 6p and O 2p orbitals, thereby reducing the activation energy of the rate-limiting *CO(2) → *COOH step by 0.6 eV, enabling a CH(3)OH production rate of 610 μmol g(-1) under light irradiation. The work deciphers the dual role of Ohmic junctions in simultaneously resolving bulk charge transport limitations and tailoring surface catalytic landscapes, establishing a universal paradigm for metal-semiconductor heterojunction photocatalyst design.