Morphology Regulation and Oxygen Vacancy Construction Synergistically Boosting the Piezocatalytic Degradation and Pure Water Splitting of SrTiO₃

In recent years, the development of high-efficiency piezoelectric materials is an effective means to make full use of the mechanical energy widely existing in the environment. However, there are few reports on multi-strategies synergistically improving piezocatalytic activity, and the mechanism of synergistic enhancement of piezocatalytic activity also receives less attention. Herein, the SrTiO₃ nanorods decorated with tunable surface oxygen vacancy concentrations are prepared. Oxygen vacancy-optimized SrTiO₃ nanorods exhibit efficient and undifferentiated piezocatalytic degradation activities for both anionic and cationic dyes under ultrasonic vibration. More importantly, it can split water into H₂ and H₂O₂ with high production rates of 540 and 332 µmol g^-1 h^-1 without adding any sacrificial agents and cocatalysts, respectively. Mechanism analyses demonstrate that the 1D structure is beneficial to mechanical energy harvesting, and the surface oxygen vacancy induces larger surface asymmetry and piezoelectric response, synergically enhancing the piezocatalytic activity of SrTiO₃ nanorods. In addition, metal deposition experiments under different conditions show that SrTiO₃ nanorods possess abundant reactive catalytic sites in the piezocatalytic reaction process. This work provides a further understanding of piezocatalysis in piezoelectric nanomaterials and is important for the development of efficient piezoelectric catalysts.