A Self-Adaptive Quantum Dots/BaTiO₃ Junction Together with Giant Charge Separation-Driving Force for CO₂...

Quantum dots (QDs) with multiple exciton generation are identified as one of the most competitive candidates for highly efficient solar-to-chemical energy conversion, yet not well recognized in excellent CO₂ photoreduction activity due to the agglomeration and exciton effect. Here, taking Zn_0.5Cd_0.5S QDs (ZCS QDs) as an example, ferroelectric BaTiO₃ (BTO) with high-energy state polarization charges is introduced to dynamically tune the properties of interfacial charges, achieving self-adaptive electrostatic adsorption of QDs and intensive photogenerated charge separation. Meanwhile, in synergy with the Z-scheme ZCS QDs/BTO heterojunction, carrier recombination is further inhibited. Such a subtle charge modulation exhibits an exceptional improvement in CO₂ photoreduction, reaching CO yields that are 15.06 times and 2.13 times those of the pure BTO and ZCS QDs, respectively. Notably, there is a remarkable 8.67 times further increase in CO yield for external polarization. The validity of the polarization charges modulating strategy for boosting CO yield is further demonstrated using the double-layer capacitance (C_dl) and in situ Fourier transform infrared spectroscopy. This study shows great promise for ferroelectric materials in CO₂ photoreduction.