Enhanced Ferroelectric Polarization in Au@BaTiO₃ Yolk‐in‐Shell Nanostructure for Synergistic Boosting Visible‐Light‐ Piezocatalytic CO₂ Reduction

Developing efficient photo-piezocatalytic systems to achieve the conversion of renewable energy to chemical energy emerges enormous potential. However, poor catalytic efficiency remains a significant obstacle to future practical applications. Herein, a series of unique Au@BaTiO₃ (Au@BT) yolk-shell nanostructure photo-piezocatalyst is constructed with single Au nanoparticle (Au NP) embedded in different positions within ferroelectric BaTiO₃ hollow nanosphere (BT-HNS). This special structure showcases excellent mechanical force sensitivity and provides ample plasmon-induced interfacial charge-transfer pathways. In addition, the powerful piezoelectric polarization electric field induced by the enhanced ferroelectric polarization electric field via corona poling treatment in BT-HNS further promotes charge separation, CO₂ adsorption and key intermediate conversion. Notably, BT with single Au NP encapsulated into hollow nanosphere shell with reinforced polarization (Au@BT-1-P) shows synergistically improved photo-piezocatalytic CO₂ reduction activity for producing CO with a high production rate of 31.29 µmol g^-1 h^-1 under visible light irradiation and ultrasonic vibration. This work highlights a generic tactic for optimized design of high-performance and multifunctional nanostructured photo-piezocatalyst. Meanwhile, these yolk-in-shell nanostructures with single Au nanoparticle as an ideal model may hold great promise to inspire in-depth exploration of carrier dynamics and mechanistic understanding of the catalytic reaction.