Pure BiFeO₃, Bi₂Fe₄O₉, and BiFeO₃/Bi₂Fe₄O₉ heterostructure nanofibers were successfully synthesized by a facile wet chemical process followed by an electrospinning technique. Compared with the pure BiFeO₃ and Bi₂Fe₄O₉ nanofibers, the introduction of Bi₂Fe₄O₉ in the BiFeO₃ makes its absorption edge red shift to absorb much more visible light, and improves its separation efficiency of photogenerated carrier. Besides, the as-obtained BiFeO₃/Bi₂Fe₄O₉ nanofibers exhibit higher photocatalytic activity in both the degradation of Rhodamine B and H₂ evolution from water under visible-light irradiation. The BiFeO₃/Bi₂Fe₄O₉ nanofibers exhibited about 2.7 times and 2.0 times higher H₂ evolution than that of pure BiFeO₃ and pure Bi₂Fe₄O₉ samples, respectively. The possible photoreactive mechanism of the BiFeO₃/Bi₂Fe₄O₉ nanofibers was carefully investigated according to the results of photocatalytic and photoelectric performance, and a Z-scheme mechanism was proposed. Such BiFeO₃/Bi₂Fe₄O₉ heterostructure and its composing strategy may bring new insight into the designing of highly efficient visible-light-responsible photocatalysts.

中文翻译：

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BiFeO ₃ / Bi ₂ Fe ₄ O ₉异质结纳米纤维的表面合成及光反应机理

通过简便的湿化学工艺和静电纺丝技术成功地合成了纯BiFeO ₃，Bi ₂ Fe ₄ O ₉和BiFeO ₃ / Bi ₂ Fe ₄ O ₉异质结构纳米纤维。与纯的BiFeO相比₃和Bi ₂的Fe ₄ ø ₉纳米纤维，引入的Bi ₂的Fe ₄ ø ₉中的BiFeO ₃使其吸收边缘发生红移以吸收更多的可见光，并提高了光生载流子的分离效率。此外，所获得的BiFeO ₃ / Bi ₂ Fe ₄ O ₉纳米纤维在若丹明B的降解和H ₂在可见光照射下从水中析出时均表现出较高的光催化活性。与纯BiFeO ₃和纯Bi ₂ Fe ₄ O ₉相比，BiFeO ₃ / Bi ₂ Fe ₄ O ₉纳米纤维的H ₂析出速率高约2.7倍和2.0倍。样本。根据光催化和光电性能的结果，仔细研究了BiFeO ₃ / Bi ₂ Fe ₄ O ₉纳米纤维可能的光反应机理，并提出了Z-机理。这样的BiFeO ₃ / Bi ₂ Fe ₄ O ₉异质结构及其组成策略可能为高效可见光响应型光催化剂的设计带来新的见解。