Interfacial Engineering and Active Species Modulation in Gd and Zr Codoped BiFeO3 with BaTiO3 Composite Nanoparticles for Superior Synergistic Piezo-Photocatalysis of Ofloxacin

This study demonstrates a tripartite strategy to significantly enhance the piezo-photocatalytic degradation of ofloxacin (OFL) using modified BTO@BGFZ9 composite nanoparticles. Gd/Zr codoping optimizes the band structure and ferroelectricity of BFO, while heterojunction construction with BTO promotes interfacial charge separation. Corona poling treatment further aligns ferroelectric domains to amplify the piezoelectric field. The optimized 0.4BTO@BGFZ9 composite achieved 88.96% OFL degradation within 120 min under ultrasonic and visible-light synergy with a first-order rate constant of 0.0175 min–1. Mechanistic studies reveal that VO and a type-II heterojunction facilitate the generation of dominant reactive species (•O2– and h+), enabling efficient OFL mineralization via piperazine ring cleavage and defluorination.