光电化学(PEC)技术作为一种简单的太阳能转换装置，是解决环境和能源挑战最有前途的方法之一。PEC技术主要涉及到在光照射下光活性材料被激发导致载流子生成和电荷转移，进而发生光电转换的过程，活性材料在整个系统中起着核心作用。因此，获得高效PEC性能的关键是设计和合成高光电活性材料。光活性材料的光电转化效率主要取决于较宽的光吸收响应范围和较快的光生载流子分离和传递速率。常见的光敏半导体可以作为光电活性材料，包括金属氧化物、金属硫化物、有机小分子和有机聚合物等。但是由于单个半导体材料的固有局限性，难以满足不断增长的检测需求。探索具有特定结构组成的功能复合材料可以克服单个半导体材料的性能缺陷。此外，太阳光谱中紫外光区仅占约5%，而可见光占比约45%。研发可见光驱动的光电活性材料例如银基、铋基、有机聚合物材料等对于PEC技术的商业应用具有更重要意义。由于BiOX (X = Cl, Br, I)基材料具有带隙可调、独特的层状结构、无毒性、光吸收范围宽、光稳定性优异等特点，基于BiOX (X = Cl, Br, I)的PEC技术已成为研究热点。本文介绍了BiOX (X = Cl, Br, I)基材料的理化性质，从提升太阳光的利用率、抑制光生电子和空穴的复合着手，从表面和界面两个角度讨论了BiOX (X = Cl, Br, I)基材料的改性方法，重点介绍了其在微结构调控、表面缺陷、官能团修饰、金属沉积、杂原子掺杂和异质结构建等方面的研究进展。通过不同的设计策略，可以有效地提高BiOX (X = Cl, Br, I)光生载流子的分离效率，从而提高其PEC性能。介绍了改性BiOX (X = Cl, Br, I)在PEC传感、光电水分解、光电催化降解、CO₂还原、固氮和光催化燃料电池等方面的应用。最后，讨论了BiOX (X = Cl, Br, I)材料在上述应用中面临的挑战，并对BiOX (X = Cl, Br, I)材料未来的研究和实际应用进行了展望。

采用两步水热法制备了BiSbO₄/BiOBr复合材料，并对其微观形貌、物相结构、化学组成、光学性能、光催化性能进行测试。结果表明：由纳米棒组成的BiSbO₄成功负载到片状BiOBr表面，二者产生的异质结结构不仅拓宽了催化剂的光响应范围还提升了光生电子-空穴对分离效率。其在模拟可见光下的光催化性能都优于单一的BiSbO₄和BiOBr，当BiSbO₄在复合材料中的质量分数为6%时，所制备的复合材料的光催化降解亚甲蓝(MB)性能最佳，其在模拟可见光下照射120 min后对MB的降解率达91.3%，经过4次循环后降解率仍有77.4%。

Cs_xWO₃/TiO₂ composites with full‐spectrum catalytic activity were prepared by solvothermal reaction. The composites were characterized using X‐ray diffraction (XRD) analysis, scanning electron microscopy (SEM), transmission electron microscopy (TEM), specific surface area testing, X‐ray photoelectron spectroscopy (XPS), and UV‐Vis diffuse reflectance spectra (UV‐Vis DRS). Cs_xWO₃ and TiO₂ were uniformly bonded together in the composites. The heterojunction structure was formed. The band gap was reduced from 2.75 to 2.65 eV. The photocatalytic property of Cs_xWO₃/TiO₂ was demonstrated by the degradation rates of 20 mg·L^-1 methylene blue dye, which were 99.7%, 91.4%, and 70.7% under irradiation from a 300 W high‐pressure mercury lamp, a 500 W xenon lamp, and a 400 W infrared lamp, respectively. After five cycles of photocatalytic degradation, the composite photocatalyst still showed a degradation efficiency of 87.6%. This indicates that Cs_xWO₃/TiO₂ has good photocatalytic degradability and cyclic stability. The photocatalytic mechanism of Cs_xWO₃/TiO₂ was investigated. The trapping experiments of the active species showed that the main active substances were the empty hole (h⁺) and hydroxyl radical (·OH).