Synergistic Bulk‐Surface Engineering of Ferroelectric PbTiO3: Polarization Amplification and Surface Carrier Confinement for Efficient Photo‐Thermal Coupled Catalytic CO2‐to‐Fuel Conversion

Abstract Semiconductor photocatalysis is severely constrained by sluggish photogenerated carrier dynamics, especially under high‐temperature conditions inherent to photo‐thermal coupled catalysis. Herein, using ferroelectric PbTiO 3 (PTO) as example, a synergistic bulk‐surface engineering strategy that integrates polarization amplification with surface carrier confinement to address this challenge is reported. Through hydrothermal synthesis, Pt 2 ⁺ is incorporated into the PTO lattice by partially substituting Ti⁴⁺ sites, which not only enhances PTO's intrinsic polarization but introduces impurity energy levels, jointly suppressing bulk carrier recombination. Critically, the incorporation of Pt elevates the Curie temperature of PTO from 550 to 650 °C, stabilizing its ferroelectric properties under high‐temperature environments. Leveraging PTO's polarization‐induced charge migration, two co‐catalysts are selectively photodeposited on opposite (001) facets of Pt‐doped PTO, realizing spatial isolation of surface carrier trappers to inhibit surface carrier recombination. A detailed carrier dynamics study demonstrated this elaborated bulk‐surface engineering dramatically prolongs the average photocharge lifetime, while Pt doping‐mediated interfacial barrier reduction promotes high surface carrier localization. Consequently, the optimized PR‐Au/MnO x ‐2%‐PTPO exhibits exceptional photo‐thermal coupled catalytic CO 2 hydrogenation performance at 550 °C, with CO production rate reaching 235.7 mmol·g −1 ·h −1 , ≈6.6 times that of pure PTO. This study establishes a novel modulation paradigm for ferroelectric semiconductors in efficient energy conversion.