Local polarization electric field promoted the active sites formation on the piezo-photocatalytic BaCaBO3F containing OVs and N doping to effectively degradation of oxytetracycline in water

Piezoelectric polarized electric fields in non-centrally symmetric materials can enhance photocatalytic activity by inhibiting the recombination of photogenerated carriers. However, the catalytic performance of the unmodified piezo-photocatalyst is still not satisfactory, and it restricts its practical application in the field of piezo-photocatalysis. Herein, this study focuses on oxygen vacancies (OVs) and N doping to improve the catalytic activity of BCBF-OV2 piezo-photocatalyst. The effect of OVs and N doping on the efficient degradation of oxytetracycline (OTC) was explained through experimental research and characterization. The results indicate that the co-modified sample (BCBF-OV2) exhibited the highest OTC removal efficiency of 91.9 % after 30  min of reaction, with a kinetic constant 2.3 times higher than that of pristine BCBF. The potential mechanism for improving the piezo-photocatalytic activity of BCBF-OV2 has been revealed by PFM, KPFM and free radical quantification experiments. The presence of OVs and N doping leads to the generation of intermediate energy levels to reduce the energy barrier and promote the charge transfer between O 2 /H 2 O and BCBF-OV2 to enhance radical generation. Besides, BCBF-OV2 could also degrade a variety of pollutants and exhibit excellent catalytic properties. This study provides a deep understanding of the regulatory mechanism of N doping and OVs synergistically enhancing piezo-photocatalytic activity.