Ba substituted SrTiO3 induced lattice deformation for enhanced piezocatalytic removal of carbamazepine from water

Removal of pharmaceuticals and personal care products (PPCPs) from water by mechanical energy-driven piezocatalysis is a promising technology for environmental remediation that highly depends on the design of efficient piezocatalyst. In this study, Ba-substituted SrTiO3 piezoelectric materials were constructed and used for piezocatalytic degradation of carbamazepine (CBZ) from water. The Ba0.5Sr0.5TiO3 (BSTO-2) achieved the optimal performance, exhibiting 94.5% removal efficiency for CBZ (10 mg/L) after 30 min in the presence of BSTO-2 (0.5 g/L) and ultrasonic vibration (40 kHz, 100 W) with the minimal energy consumption. The kinetic rate constant was up to 0.106 min-1, which were 1.86 and 2.08 times as high as that of pure SrTiO3 and BaTiO3, respectively. The enhanced piezocatalytic activity was attributed to its distorted structure and modified conductivity, resulting in a higher piezoelectric response and faster interfacial charge transfer. The involved reactive species, the effects of operational condition (catalyst dosage, CBZ concentration, solution pH, anions, water matrices and different pollutants), and the possible degradation products and their toxicity were discussed in detail. The work is of great significance to develop highly efficient piezocatalysts and highlights the potential of piezocatalysis in water remediation.