A Novel Strategy for Excellent Piezocatalytic Activity in Lead-Free BaTiO 3 -Based Materials via Manipulating the Multiphase Coexistence.

Piezocatalysis is regarded as a fascinating technology for water remediation and possible disease treatment. A high piezoelectric coefficient ( d 33 ) is one of the most important parameters to determine piezocatalytic performance, which can be manipulated via phase boundary design. Herein, a novel strategy for excellent piezocatalytic activity in lead-free BaTiO 3 -based materials via manipulating the multiphase coexistence is proposed. The piezocatalyst of 0.82Ba(Ti 0.89 Sn 0.11 )O 3 -0.18(Ba 0.7 Ca 0.3 )TiO 3 (0.82BTS-0.18BCT) with multiphase coexistence is prepared, and a large d 33 can be obtained. As a result, 0.82BTS-0.18BCT exhibits excellent piezocatalytic performance for the degradation of Rhodamine B (RhB). Furthermore, the removal rate of RhB could reach more than 90% after vibration for 30 min, and the reaction rate constant ( k ) could reach 0.0706 min -1 , which is much superior to that of most other representative perovskite-structured piezoelectric materials. Excellent piezocatalytic performance can be attributed to the strong local ferro-/piezoelectric response induced by the multiphase coexistence, as confirmed by the in situ piezoresponse force microscopy (PFM). Finally, the piezocatalytic degradation mechanism is analyzed systemically and proposed. This work not only provides a high-efficiency piezocatalyst but also sheds light on developing efficient BT-based piezocatalysts by manipulating the multiphase coexistence.