Identifying intrinsic piezoelectric contribution in promoting piezocatalytic activity

Understanding the intrinsic role of piezoelectricity is critical for the rational design of high-efficiency piezocatalytic systems. However, this remains challenging due to the contribution of intrinsic piezoelectricity often being obscured by complex interface effects, specific surface area (size confinement), and other coupled phenomena. In this study, we decouple these factors by employing a model system of piezoceramic thin sheets with a tunable piezoelectric coefficient (d₃₃). We establish a direct and quantitative relationship between d₃₃ and catalytic activity: the sheet with the highest d₃₃ value of 754 pC N^-1 exhibited a superior H₂O₂ production rate of 8.58 μmol h^-1 and a Rhodamine B degradation rate constant of 0.073 min^-1. Conversely, the sample with the lowest d₃₃ value of 155 pC N^-1 showed the minimal activity. Through carrier dynamics analysis and carrier migration simulations, we demonstrate that stronger piezoelectricity enables more efficient polarization rearrangement, greater stress sensitivity, and improved charge separation and transport. These effects lead to a higher transient free carrier concentration and a more robust built-in electric field, which ultimately accelerate the piezocatalytic reaction kinetics. This work establishes a clear and quantitative correlation between intrinsic piezoelectric properties and catalytic activity, while also delivering a high-performance, easily synthesized piezocatalytic platform for sustainable applications.