A novel BiNbO₄/Bi₂S₃ nanocomposite was successfully synthesized by combining precipitation, heat‐treatment, and ion exchange technique. The corresponding crystal structure, morphology, chemical components, and adsorption isotherm were fully characterized. The visible‐light photocatalytic performance was investigated in the degradation reaction of Rhodamine B (RhB). Compared to the conversions obtained using BiNbO₄ (47%) or Bi₂S₃ (52%) as the photocatalyst (80 min), BiNbO₄/Bi₂S₃ composite demonstrated a much higher photocatalytic efficiency with conversion up to 87% and great durability. The best fitting of photodecomposition of RhB into a first‐order reaction gave an observed rate constant of k _obs= 3.46 ± 0.33 × 10⁻² min⁻¹ (t_1/2=20.0 min). Our active species trapping experiment confirms that photoexcited holes and •O₂⁻ radicals formed in situ under photoexcitation directly oxidize the dye molecules. The improved photocatalytic activity was likely due to the decrease of charge recombination rate resulted from possible interfacial charge transfers through the heterojunction.

中文翻译：

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具有改进的可见光光催化活性的BiNbO4 / Bi2S3纳米复合材料的合成与表征

结合沉淀，热处理和离子交换技术成功合成了新型的BiNbO ₄ / Bi ₂ S ₃纳米复合材料。充分表征了相应的晶体结构，形态，化学成分和吸附等温线。在若丹明B（RhB）的降解反应中研究了可见光的光催化性能。与使用BiNbO ₄（47％）或Bi ₂ S ₃（52％）作为光催化剂（80分钟）获得的转化率相比，BiNbO ₄ / Bi ₂ S ₃复合材料表现出更高的光催化效率，转化率高达87％，并且具有出色的耐久性。RhB的光分解最适合一级反应，观察到的速率常数为k _obs = 3.46±0.33×10 ^-2  min ^-1（t _1/2 = 20.0 min）。我们的活性物质捕集该光激发的空穴和实验证实•Ø ₂ ^-原位形成的下光激发自由基直接氧化氧化的染料分子。改善的光催化活性可能是由于可能通过异质结进行界面电荷转移而导致的电荷复合速率降低。