In this work, a hierarchical BiOBr/Bi₂₄O₃₁Br₁₀ heterojunction is prepared for the first time from a bismuth MOF (Bi-BTC) by a facile bromination–annealing route. Since cetyltrimethylammonium bromide (CTAB) is used as the Br element source, the heterojunction constructed of BiOBr and Bi₂₄O₃₁Br₁₀ nanosheets maintains the rod-like morphology of the original MOF. In photocatalytic degradation tests, the BiOBr/Bi₂₄O₃₁Br₁₀ heterojunction exhibits much higher photocatalytic activity than pure Bi₂O₃, and the heterojunctions annealed at 450 °C show the best photocatalytic activity among samples prepared at various temperatures. The heterojunction also shows good pH adaptability, good reusability, and structural stability for RhB degradation, and the TOC results and full UV-vis spectra confirm its good mineralization performance under visible-light irradiation. Based on the photo-electrochemical characterization and free radical tests, a photocatalytic enhancement mechanism over the heterojunction and different photocatalytic reactions in the presence of photo-induced h⁺, ˙O₂⁻ and ¹O₂ are reasonably proposed.

中文翻译：

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铋MOF衍生的BiOBr / Bi24O31Br10异质结具有增强的可见光光催化性能

在这项工作中，通过便捷的溴化-退火路线，从铋MOF（Bi-BTC）首次制备了分级BiOBr / Bi ₂₄ O ₃₁ Br ₁₀异质结。由于十六烷基三甲基溴化铵（CTAB）被用作Br元素源，由BiOBr和Bi ₂₄ O ₃₁ Br ₁₀纳米片构成的异质结保持了原始MOF的棒状形态。在光催化降解测试中，BiOBr / Bi ₂₄ O ₃₁ Br ₁₀异质结表现出比纯Bi ₂ O ₃高得多的光催化活性。，并且在450°C退火的异质结在不同温度下制备的样品中显示出最佳的光催化活性。异质结还显示出良好的pH适应性，良好的可重复使用性以及RhB降解的结构稳定性，并且TOC结果和完整的UV-vis光谱证实了其在可见光照射下的良好矿化性能。基于所述光电化学表征和自由基的测试中，在异质结光催化增强机制以及在光致小时存在不同光催化反应⁺，邻₂ ^-和¹ ö ₂合理地提出。