A novel visible-light responsive layered perovskite photocatalyst Bi₄MO₈X (M = Nb, Ta; X = Cl, Br) has been successfully constructed using BiOX (X = Cl, Br) via a solid state method. The as-prepared samples were characterized by XRD, SEM, HRTEM, EDS, element mapping, XPS and UV-vis spectra to determine the structures, morphologies and optical properties. Photocatalytic activities were conducted under simulated sunlight as well as visible light and evaluated by the efficiency of hydrogen evolution. Among these photocatalysts, the photocatalytic capability of hydrogen generation for Bi₄NbO₈X was better than that of Bi₄TaO₈X (X = Cl, Br), while Bi₄NbO₈Br showed the best performance for photocatalytic hydrogen production. Moreover, these photocatalysts exhibited excellent activity for hydrogen generation when glycerol was utilized as a sacrificial agent, which could be assigned to its low standard oxidation potential and the number of α-OH groups. Furthermore, we demonstrated that the structural properties of Bi₄NbO₈Br were beneficial for the mobility of photocarriers. The reason for this can be ascribed to the [Bi₂O₂]²⁺ structures with lower twisting degree, as evidenced by the Raman spectra analysis.

中文翻译：

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使用BiOX（X = Cl，Br）构造 的可见光驱动新型层状钙钛矿氧化物卤化物Bi ₄ MO ₈ X（M = Nb，Ta; X = Cl，Br）用于增强光催化氢的释放

一种新型的可见光响应层状钙钛矿光催化剂Bi ₄ MO ₈ X（M = Nb，Ta; X = Cl，Br）已通过固相法成功地使用BiOX（X = Cl，Br）构造。通过XRD，SEM，HRTEM，EDS，元素图谱，XPS和UV-vis光谱对制备的样品进行表征，以确定其结构，形态和光学性质。在模拟阳光和可见光下进行光催化活性，并通过析氢效率进行评估。在这些光催化剂中，Bi ₄ NbO ₈ X的氢气产生的光催化性能要好于Bi ₄ TaO ₈ X（X = Cl，Br），而Bi₄ NbO ₈ Br在光催化制氢方面表现出最好的性能。此外，当将甘油用作牺牲剂时，这些光催化剂表现出优异的产氢活性，这可以归因于其低标准氧化电位和α-OH基团的数量。此外，我们证明了Bi ₄ NbO ₈ Br的结构性质有利于光载流子的迁移。其原因可以归因于扭曲度较低的[Bi ₂ O ₂ ] ²⁺结构，如拉曼光谱分析所证明的。