Study on the piezo-photocatalytic performance of ZnFe2O4/BaTiO3@alumina hollow particles (ZBA) for tetracycline degradation

To overcome the limitations of traditional photocatalysts in treating persistent and biologically hazardous pollutants, this study employed the sol–gel method using hollow alumina nanoparticles as a template to successfully synthesize a hollow ZnFe 2 O 4 /BaTiO 3 @alumina (ZBA) composite material. The prepared ZBA composite exhibited enhanced photocatalytic activity for the degradation of tetracycline (TC), achieving a degradation rate of 84% within 60 min—values that were 2.72-fold, 1.81-fold, and 1.33-fold higher, respectively, than those observed for ZnFe 2 O 4 , BaTiO 3 , and ZnFe 2 O 4 /BaTiO 3 . This performance enhancement can be primarily attributed to its coupled piezoelectric–photocatalytic process, which facilitates charge transfer and reduces the recombination of photogenerated carriers. Free radical trapping experiments confirmed that OH − , O 2 − , and h + are the dominant active species involved in the degradation of TC. Furthermore, the hollow alumina support structure improved light utilization efficiency, catalyst dispersion, and magnetic recovery capability. These results demonstrate that the ZBA composite material is an efficient multifunctional photocatalyst with significant potential for practical wastewater treatment applications.