Improving catalytic performance of (Ba, Ca) (Ti, Sn)O₃ piezoelectric ceramics by regulating phase structure

Piezocatalysis is considered as an evolving technology based on the piezoelectric properties of catalysts, has shown great potential in the field of environmental remediation, water splitting, and biotechnology. In this work, the catalytic performance of (Ba_0.95Ca_0.05) (Ti_1-xSn_x)O₃ (BCT_1-xS_x, 0.04 ≤ x ≤ 0.12) piezoelectric ceramics was studied systematically. The relationship between piezoelectric performance and piezo-photocatalytic performance was investigated. As the Sn content increased, the crystalline structure gradually changed from the orthorhombic (O) phase (x = 0.04) to O-pseudocubic (PC) two-phase coexistence (x = 0.08 and x = 0.10), and finally to the PC phase (x = 0.12). The piezoelectric constant d₃₃ exhibited an initial increases followed by a decreases with rising Sn content, reaching peak of 509pC/N at x = 0.10. The enhanced d₃₃ was due to multiphase coexistence and a Curie temperature near room temperature. The piezocatalytic efficacy of BCT_1-xS_x was linked to d₃₃, with the maximum degradation rate achieved at x = 0.10. However, the optimal piezo-photocatalytic performance was obtained at x = 0.08 instead of x = 0.10 with the highest degradation rate of 69%. The photo-piezocatalytic performance was discovered to be intricately linked not only to the band gap of piezocatalysts but also influenced by their piezoelectric properties. These results will provide guidance for designing new lead-free piezoelectric materials with excellent catalytic properties.