The performances of photoelectrochemical (PEC) sensors mainly depend on the physical/chemical properties of photoactive materials. Therefore, the preparation of semiconductors with strong light absorption capacity, high photoelectric conversion efficiency, effective carrier separation and good light stability, has received much interest in the field of PEC sensing. As bismuth oxyhalides (BiOX, X = Cl, Br, I)-based photocatalysts present wider light absorption range, adjustable band gap and good light stability, they have been widely studied and applied in PEC sensing. This paper reviews the functionalization methods of BiOX and highlights the impact of functionalization on their morphology, composition, structure and properties. Importantly, the sensing strategies of BiOX-based functional materials in photoanodic and photocathodic sensing are systematically summarized. Finally, the challenges and opportunities for the BiOX-based PEC sensors are prospected.

光电化学（PEC）传感器的性能主要取决于光敏材料的物理/化学特性。因此，具有强光吸收能力，高光电转换效率，有效的载流子分离和良好的光稳定性的半导体的制备已经在PEC感测领域中引起了很大的兴趣。由于基于卤氧化铋（BiOX，X = Cl，Br，I）的光催化剂具有较宽的光吸收范围，可调节的带隙和良好的光稳定性，因此已被广泛研究并应用于PEC传感中。本文回顾了BiOX的功能化方法，并重点介绍了功能化对其形态，组成，结构和性能的影响。重要的，系统地总结了BiOX基功能材料在光阳极和光阴极传感中的传感策略。最后，展望了基于BiOX的PEC传感器的挑战和机遇。