<p>Photoelectrocatalytic processes for detoxifying ofloxacin in hyposaline wastewater encounter significant challenges, primarily stemming from a weak built-in electric field (IEF) that causes inefficient separation of photogenerated carriers, coupled with low reaction activity. In this work, we introduce a crystal dipole engineering strategy that leverages high-valence Mo-BiVO₄ to enhance both photoelectrocatalytic activity and detoxification efficiency, as demonstrated by the improved performance of BiVO₄ in degrading ofloxacin. Mo atoms are incorporated into the BiVO₄ lattice to break the symmetry, significantly enhancing the crystal dipole moment. This augmentation intensifies IEF within BiVO₄, thereby promoting directional carrier migration. Optimized IEF reached 2.05 times that of pristine BiVO₄. Mo-doped BiVO₄ photoanodes exhibit remarkable enhancement in electron-hole separation efficiency, playing a pivotal role in photoelectrocatalytic applications. Remarkably, 4% Mo-BiVO₄ achieved 96.5% ofloxacin degradation within 60 min. Remarkably, it maintains 91.9% degradation efficiency in natural lake water containing saline and organic interferents, high-lighting its exceptional anti-interference capability. This work elucidates a strategy for boosting photocatalytic performance through unit-cell dipole engineering and enhanced IEF, aiming to enhance the sustainability of wastewater treatment processes.</p>