It is of great significance to construct heterojunctions using industrially produced co-catalysts. The direct Z-scheme composite photocatalyst provides an effective separation of photogenerated carriers. Herein, a kind of novel 2D/3D direct Z-scheme NiFe-LDH/Zn_0.5Cd_0.5S is prepared. Compared with fresh catalysts, the NiFe-layered double hydroxide (LDH)/Zn_0.5Cd_0.5S composite exhibits advantages including excellent visible light response ability and photoelectric performance and improved H₂ evolution rate by 11.6 times. Combining with theoretical calculations, ESR, XPS, and experimental results, the direct Z-scheme mechanism of the photocatalytic reaction is proposed. There is a channel for electron transfer between Zn_0.5Cd_0.5S and NiFe-LDH, and the electrons of Zn_0.5Cd_0.5S directly combine with the valence band holes of NiFe-LDH. Finally, the electrons remaining on NiFe-LDH can reduce H⁺ to generate H₂. This process effectively achieves separation of photogenerated carriers and increases photocatalytic H₂ evolution.

中文翻译：

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用于光催化析氢的直接 Z 型异质结 NiFe 层状双氢氧化物 (LDH)/Zn0.5Cd0.5S 的构建

使用工业生产的助催化剂构建异质结具有重要意义。直接 Z 型复合光催化剂提供了光生载流子的有效分离。在此，制备了一种新型的 2D/3D 直接 Z 型 NiFe-LDH/Zn _0.5 Cd _0.5 S。与新鲜催化剂相比，NiFe层状双氢氧化物（LDH）/Zn _0.5 Cd _0.5 S复合材料具有优异的可见光响应能力和光电性能以及改进的H ₂进化速度提高了 11.6 倍。结合理论计算、ESR、XPS和实验结果，提出了光催化反应的直接Z型机制。存在用于锌之间的电子转移的通道_0.5镉_0.5 S和由NiFe-LDH和Zn的电子_0.5镉_0.5 š直接与由NiFe-LDH的价带空穴结合。最后，保留在 NiFe-LDH 上的电子可以还原 H ⁺以生成 H ₂。该过程有效地实现了光生载流子的分离并增加了光催化H _{2 的}析出。