Unguided electron transfer presents challenges for selectively photo-reducing carbon dioxide (CO₂) into C₂ products. We constructed continuous inter- and intra-component electric fields within photocatalysts by in situ chemical encapsulation. The dual-tandem electric fields facilitate charge separation and transfer photogenerated electrons accurately toward Cu²⁺-Cu⁺ sites for C–C coupling. We tracked the electron transport, observing directional electron migration between contacted heterostructure atoms, ligand carbon atoms, and Cu²⁺-Cu⁺ centers. The as-synthesized photocatalyst manifests a remarkable ethane (C₂H₆) production rate of 16.3 μmol g⁻¹ h⁻¹, a high electron selectivity of 64.4% for C₂H₆, and a stable electron consumption yield of 354.6 μmol g⁻¹ h⁻¹ in water vapor. These represent one of the best performances for CO₂ photoreduction. This work promotes charge separation and manages precise control over electron migration via tandem built-in electric fields, opening a new prospect for selective CO₂ photoreduction into high-value chemicals.

无引导的电子转移对选择性光还原二氧化碳(CO ₂ )生成C ₂产品提出了挑战。我们通过原位化学封装在光催化剂内构建了连续的组分间和组分内电场。双串联电场促进电荷分离并将光生电子准确地转移到 Cu ²⁺ -Cu ⁺位点以进行 C-C 耦合。我们跟踪电子传输，观察接触的异质结构原子、配体碳原子和Cu ²⁺ -Cu ⁺中心之间的定向电子迁移。所合成的光催化剂表现出显着的乙烷(C ₂ H ₆ )产率为16.3 μmol g ^-1 h ^-1 、对C ₂ H ₆的高电子选择性为64.4%以及稳定的电子消耗产率为354.6 μmol g ^-1 h ^-1在水蒸气中。这些代表了CO ₂光还原的最佳性能之一。这项工作通过串联内置电场促进电荷分离并精确控制电子迁移，为选择性CO ₂光还原转化为高价值化学品开辟了新前景。