Highly-efficient piezocatalytic performance of nanocrystalline BaTi_0.89Sn_0.11O₃ catalyst with T c near room temperature

Highlights: • Nanocrystalline BaTi_0.89Sn_0.11O₃ with a coexistence of C+R+T+O phases have been prepared successfully. • A superior piezocatalytic performance is obtained for the dyes degradation and hydrogen generation near T_c. • An efficient pyrocatalysis with BaTi_0.89Sn_0.11O₃ nanoparticles is found under cold–hot cycle excitation near T_c. • Employing low T_c ferroelectrics by harvesting vibration or thermal energy from the surroundings for water remediation. Inducing changes in polarization of a ferroelectric material by applied stress is recently regarded as a fascinating approach to achieve piezocatalysis in case of both dye degradation and H₂ generation. The polarization-driven ferroelectrics are expected to reveal superior performance near Curie temperature (T_c) due to the maximum polarization change, but lack experimental proof. In this work, BaTi_0.89Sn_0.11O₃ (BTS) with high piezoelectric coefficient and low T_c is taken as an example for materials of this kind. BTS nanoparticles with multiple phase coexistence and low T_c ~ 40 °C were prepared and used for dyes degradation and hydrogen generation. In-situ piezoresponse scanning force microscopy revealed a much-enhanced piezoelectric response near T_c, resulting in a highly-active piezocatalyst. The Rhodamine B (RhB) and Methyl orange (MO) could be decomposed within 15 min and 60 min, respectively. Superior H₂ generation rates of 141.1 and 360.2 $\mu$mol g⁻¹ h⁻¹ were observed for BTS and BTS@Ag nanoparticles under ultrasonic irradiation at 15 °C. Furthermore, a highly-efficient pyrocatalytic performance with BTS nanoparticles was also found under cold–hot cycle excitation near T_c. This work demonstrates an efficient and low-cost strategy for water remediation via employing low T_c ferroelectrics by harvesting vibration or thermal energy from the surroundings.