Efficient enhancement of piezo-catalytic activity of BaTiO3-based piezoelectric ceramics via phase boundary engineering

•Two-phase coexistence of rhombohedral-orthorhombic (R-O) is achieved at room temperature in BTZSH-0.04 by simple doping.•The multiphase coexistence in BTZSH-0.04 ceramic increases the spontaneous polarization directions and declines the polarization rotation energy barrier, exhibiting an enhanced piezo-catalytic activity.•The degradation efficiency of rhodamine B (RhB) is increased from 36.14% for BT to 97.27% at 60 min for BTZSH-0.04, accompanied with an excellent cycling stability. Piezoelectric catalysis stemmed from lead-free piezoelectric ceramics is an emerging catalytic technology applied extensively in degradation of organic pollutants due to its low energy consumption and non-pollution. However, the dissatisfied catalytic efficiency of lead-free piezoelectric ceramics has constrained their further development and application. Herein, we employ ion doping to modulate the phase boundary construction of BaTiO3-based piezoelectric ceramics (BaTi(1-x)(Zr1/3Sn1/3Hf1/3)xO3, BTZSH-x), and the degradation performances of organic dyes are explored to illuminate the piezo-catalytic mechanism. The ion doping alters the phase boundary of BaTiO3 ceramics and a two-phase coexistence of rhombohedral-orthorhombic is achieved at room temperature in BTZSH-0.04 ceramic. Consequently, the BTZSH-0.04 ceramic exhibits an excellent degradation efficiency of rhodamine B with 97.27% in 60min and a high reaction rate constant of 0.056 min−1 under ultrasonication which is 7.4 times more than that of pristine BaTiO3. This work provides an advisable policy for constructing environmental-friendly piezoelectric materials with glorious piezo-catalytic activity. [Display omitted] The BaTi0.96(Zr1/3Sn1/3Hf1/3)0.04O3 (BTZSH-0.04) ceramic with modulated phase boundary, profitable energy band structure and lower charge transfer resistance generates more easier separation and more expeditious migration of electron-hole pairs under the actuation of ultrasonic vibration due to the piezoelectric effect. More abundant •O2− and •OH radicals are created by the redox reactions of electrons on the CB with O2 and holes on the VB with OH−. Consequently, a tremendous numbers of vivacious radicals generate highly efficient redox reactions with organic dyes, resulting in a delightful piezo-catalytic performance.