Single-atom Pd clusters anchored on t-BaTiO3 material was synthesized using hydrothermal and ultrasonic methods for the effective piezoelectric catalytic degradation of pollutants using vibration energy. XRD patterns of BaTiO3 loaded with monoatomic Pd were obtained before and after calcining, and showed typical cubic-phase BTO. TEM and HAADF-STEM images indicated single-atom Pd clusters were successfully introduced into the BaTiO3. The piezoelectric current density of the prepared Pd-BaTiO3 binary composite was significantly higher than that of the pristine BaTiO3. Under mechanical vibration, the nanomaterial exhibited a tetracycline decomposition rate of ~95 % within 7 h, which is much higher than the degradation rate of 56.7 % observed with pure BaTiO3. Many of the piezo-induced electrons escaped to the Pd-doped BaTiO3 interface because of Pd’s excellent conductivity. Single-atom Pd clusters help promote the separation of the piezo-induced electrons, thereby achieving synergistic catalysis. This work demonstrates the feasibility of combining ultrasonic technology with the piezoelectric effect and provides a promising strategy for the development of ultrasonic and piezoelectric materials.

1. Introduction
2. Experimental Procedure
    2.1. Chemicals
    2.2. Anchoring monoatomic Pd to BaTiO3
    2.3. Characterization and piezoelectric activity test
3. Results and Discussion
    3.1. XRD characterization
    3.2. TEM and HAADF-STEM observations
    3.3. XPS characterization
    3.4. Piezoelectric properties of the samples
    3.5. Degradation of tetracycline
4. Conclusion

• Xin Ni(Student, School of Chemistry and Life Sciences, Suzhou University of Science and Technology)
• Yuan Liang(Professor, School of Chemistry and Life Sciences, Suzhou University of Science and Technology)
• Quanzi Pan(Student, School of Chemistry and Life Sciences, Suzhou University of Science and Technology)
• Hengjie Guo(Instructor, Gold Mantis School of Architecture, Soochow University, Instructor, China-Portugal Joint Laboratory of Cultural Heritage Conservation Science Supported by The Belt and Road Initiative)
• Kai Chen(Student, School of Chemistry and Life Sciences, Suzhou University of Science and Technology)
• Bo Zhang(Student, School of Chemistry and Life Sciences, Suzhou University of Science and Technology)
• Shaocong Ni(Student, School of Chemistry and Life Sciences, Suzhou University of Science and Technology)
• Bin Sheng(Student, School of Chemistry and Life Sciences, Suzhou University of Science and Technology)
• Zeda Meng(Professor, School of Chemistry and Life Sciences, Suzhou University of Science and Technology) Corresponding Author
• Shouqing Liu(Professor, School of Chemistry and Life Sciences, Suzhou University of Science and Technology) Corresponding Author
• Won-Chun Oh(Professor, Department of Advanced Materials Science & Engineering, Hanseo University) Corresponding Author