Band-gap regulation of photocatalysts has been turned out to be a very important approach to achieve high effective utilization of solar spectrum and obtain an optimal photocatalytic property. Herein, a novel iodide modified Bi₄O₅Br₂ photocatalyst with controlled band-gap position was successfully synthesized for the first time via a simple alcoholysis-hydrolysis method at room temperature. The band structure, optical absorption properties, photo-induced charges transfer/separation rate of the synthesized samples were characterized by UV-vis DRS, Mott-Schottky method, valence band (VB) XPS, electrochemical impedance spectra and photoelectric conversion spectra. The results demonstrated that the conduction band position of Bi₄O₅Br₂ continuously decreased from 2.46 eV to 2.16 eV, and then the visible-light response and photo-generated carrier separation changes took place. Owing to the higher visible-light absorption capacity, lower interfacial charge-transfer resistance, and more efficient separation of the photoinduced charges, the iodide modified Bi₄O₅Br₂ exhibited a higher visible-light activity than pure Bi₄O₅Br₂ for the photocatalytic degradation of Bisphenol A (BPA) and NO removal under visible light irradiation. Ultimately, the repeated photodegradation experiments of BPA displayed that the obtained sample is stable and resistant to chemical or photochemical corrosion. We believe such a simple and effective strategy could pave a new way for narrowing continuously the band gap of an existed photocatalyst to control the generation and recombination rate of photo-induced carriers.

光催化剂的带隙调节已被证明是实现太阳光谱的高效利用并获得最佳光催化性能的非常重要的方法。在此，通过简单的醇解-水解方法，在室温下首次成功合成了带隙位置受控的新型碘化物修饰的Bi ₄ O ₅ Br ₂光催化剂。用紫外可见DRS，Mott-Schottky法，价带（VB）XPS，电化学阻抗谱和光电转换谱对合成样品的能带结构，光吸收性能，光致电荷转移/分离速率进行了表征。结果表明Bi ₄ O的导带位置₅ Br ₂从2.46 eV连续降低到2.16 eV，然后发生可见光响应和光生载流子分离变化。由于更高的可见光吸收能力，更低的界面电荷转移阻力以及更有效的光诱导电荷分离，碘化物修饰的Bi ₄ O ₅ Br ₂表现出比纯Bi ₄ O ₅ Br ₂更高的可见光活性。用于双酚A（BPA）的光催化降解和可见光照射下的NO去除。最终，BPA的重复光降解实验表明，所获得的样品是稳定的，并且具有抗化学腐蚀或光化学腐蚀的能力。我们认为，这种简单有效的策略可以为不断缩小现有光催化剂的带隙，控制光诱导载流子的生成和复合速率铺平道路。