Plasmon-ferroelectric Induced Multi-field Coupling Effect Accelerates Charge Spatial Separation for Boosting Tandem Photoredox Catalysis.

Integrating solar-driven CO2 reduction with organic oxidation is regarded as an ideal strategy for achieving carbon neutrality. However, enhancement of photocatalytic efficiency is persistently blocked by low photogenerated carrier yields and unavoidable fast electron/hole recombination. Herein, we propose to design a plasmonic-ferroelectric heterojunction (WO3-x/K4Nb6O17), which enhances localized electromagnetic field and ferroelectric polarization field simultaneously through the cooperative coupling of localized surface plasmon resonance effect in WO3-x and ferroelectric polarization in K4Nb6O17, thereby not only promoting energetic hot-carriers generation, but also accelerating bulk charge separation. Ultimately, hot-electrons and photoelectrons are directionally transferred and extracted to K4Nb6O17 surface for CO2 reduction, whereas massive holes are accumulated in WO3-x for benzylicalcohol activation. Under mild-conditions, WO3-x/K4Nb6O17 exhibits superior CO yield (294.76µmol·g-1·h-1), which is 9.87 and 6.27-folds higher than that of K4Nb6O17 and WO3-x, respectively. Meanwhile, compared to the simple dehydrogenation of benzylicalcohol to benzaldehyde in K4Nb6O17 and WO3-x, WO3-x/K4Nb6O17 prefers to trigger benzylicalcohol C-C coupling for directed production of more value-added hydrobenzoin (313.15µmol·g-1·h-1). This work would open a conceptual vista for designing multi-field coupling structures to facilitate charge spatial separation and directional transfer, which would inspire further establishment of efficient novel photocatalysts and solar-to-fuel conversion systems to meet the green and sustainable development goals.