Guiding electron transfer for selective C2H6 photoproduction from CO2

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.