The Effect of Structure-Sensitive TiO₂/BiOCl Heterojunction on Photocatalytic Degradation of Norfloxacin

Abstract

TiO2/BiOCl heterojunction photocatalysts were synthesized from different exposed facets (BiOCl(010) and BiOCl(001)). Both heterojunctions had higher photocatalytic activity than their respective components. The favorable energy band shifts constructed an efficient Z-scheme TiO2/BiOCl heterostructure photocatalytic system, which significantly reduced recombination and accelerated the separation rate of photogenerated carriers. Due to the different electrostatic fields inside the crystal planes of BiOCl, electrons migrate from BiOCl to the TiO2 surface through different transport paths, resulting in the charge transport distance of photogenerated electrons in BiOCl(010) being shorter than that in BiOCl(001), and the electron loss was lower. Therefore, TiO2/BiOCl(010) had a higher photocatalytic activity. Besides, the photocatalytic oxidization mechanism was proposed, TiO2/BiOCl(010) oxidizing NOF mainly via photogenerated h+, while TiO2/BiOCl(001) oxidizing NOF through h+ and ·OH. This study contributes to an in-depth understanding of the charge transfer behavior in the TiO2/BiOCl heterojunction structure and provides a reference for the design of efficient heterojunction photocatalysts.