Efficient charge relay steering in Pd nanoparticles coupled with the heterojunction for boosting CO₂ photoreduction to C₂H₆

Solar-driven CO₂ conversion to prepare value-added products is highly desirable but challenging. Central to the achievement of multi-carbon products via CO₂ photoconversion is to break the bottlenecks of C–C coupling and multi-electron transfer. Herein, a charge relay system consisting of Pd-decorated BiOCl-wrapped CuBi₂O₄ is reported by taking advantage of the synergy of Pd nanoparticles (PdNPs) and heterojunction for efficient CO₂-to-C₂H₆ photoconversion. The C₂H₆ production rate reached 167.1 µmol g⁻¹ h⁻¹ with the electron selectivity of 81.1% in the absence of any sacrificial agents. The spectroscopic characterizations indicated that BiOCl nanosheets, acting as the charge relay, directionally transferred the photogenerated electrons from itself and CuBi₂O₄ nanorods to PdNPs for C–C coupling. The coordinated ensemble of PdNPs and heterojunction significantly elevated the charge separation and transfer efficiency. Moreover, the in-situ spectroscopic analysis supported by theoretical simulations demonstrated that the electron-rich PdNPs generated by the charge relay of PdNPs and heterojunction optimized the CO₂-to-C₂H₆ reaction pathway and reduced the energy barrier of the key *CHOCO intermediates. This work develops an innovative strategy to design the multifunctional catalysts for the photoconversion of CO₂ to value-added carbon products.