A highly-matched semiconductor/cocatalyst is crucial to enhance the bulk charge separation and surface reaction kinetics of the photoelectrode in the solar water splitting system. In this work, well-aligned, hierarchical zinc-iron layered double hydroxide (LDH) is in situ synthesized on the surface of TiO₂ by a facile and effective photo-assisted electrodeposition (PED) method. An experimental-computational combination study reveals that the photogenerated holes of TiO₂ tend to travel to ZnFe-LDH which enhances the bulk charge separation; while ZnFe-LDH acts as a cocatalyst which accelerates the surface water oxidation reaction. The resulting TiO₂/ZnFe-LDH-PE photoanode exhibits a largely enhanced PEC performance: the photocurrent density at 1.0V vs. RHE is 2.29 and 1.31 times higher than that of the pristine TiO₂ and TiO₂/ZnFe-LDH-E (prepared by a conventional electrosynthesis method) photoanode, with 150mV and 50mV of negative shift for onset potential. This can be ascribed to the enhanced interface interaction and highly-matched band structure between ZnFe-LDH and TiO₂. It is expected that this strategy can be extended to other heterostructures for advanced performance in the fields of energy conversion and storage.

中文翻译：

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光辅助合成锌铁层双氢氧化物/ TiO2纳米阵列以实现高效光电化学水分解

高度匹配的半导体/助催化剂对于增强太阳能分水系统中光电电极的整体电荷分离和表面反应动力学至关重要。在这项工作中，通过简便有效的光辅助电沉积（PED）方法在TiO ₂的表面上原位合成了排列良好的分层锌铁层双氢氧化物（LDH）。实验与计算相结合的研究表明，TiO ₂的光生空穴倾向于行进到ZnFe-LDH，从而增强了电荷的分离。ZnFe-LDH作为助催化剂，可加速地表水的氧化反应。生成的TiO ₂/ ZnFe-LDH-PE光电阳极表现出大大增强的PEC性能：1.0V vs. RHE的光电流密度是原始TiO ₂和TiO ₂ / ZnFe-LDH-E的光电流密度的2.29倍和1.31倍（由常规方法制备）电合成法）的光阳极，具有150mV和50mV的负移，用于起始电位。这可以归因于ZnFe-LDH和TiO ₂之间增强的界面相互作用和高度匹配的能带结构。可以预期，该策略可以扩展到其他异质结构，以提高能量转换和存储领域的性能。