Huai Shuangshuang, Li Xiang, Li Ping, Zhang Shijian, Huang Xiuxiu, Ruan Wenbin, Chen Jianli, Tang Zhi, Zhao Xiaoli, Liu Hewen, Wang Xiufang
Anhui Province Key Laboratory of Advanced Building Materials, Anhui Jianzhu University, Hefei, 230601, China.
School of Chemistry and Materials Science, University of Science and Technology of China, Hefei, 230026, China.
Adv Sci (Weinh). 2025 Jul 30:e09030. doi: 10.1002/advs.202509030.
Photoelectrochemical (PEC) water reduction offers a promising method for generating "green" hydrogen. The hydrogen evolution reaction (HER) at the photocathode is significantly constrained, primarily because of the rapid recombination of photogenerated electron-hole pairs and the high energy barrier encountered during the water splitting step. Here, a unique "sandwich" structure FeOOH/CuO/ZnO composite photocathode is fabricated by hydrothermal and electrodeposition methods. Photogenerated holes are extracted and transferred from the CuO to FTO substrates more easily via the introduction of FeOOH as a hole storage/transport layer. Charge recombination is hindered by the ZnO layer, which functions an electron transfer agent. Hence, the FeOOH/CuO/ZnO photocathode presents remarkable PEC water reduction capability. The maximum photocurrent density of the FeOOH/CuO/ZnO photocathode (-2.54 mA·cm) is 12.7 times greater than that of pristine CuO (-0.2 mA·cm) at 0 V. The IPCE of FeOOH/CuO/ZnO reaches 33.7% (455 nm), which is 8.1 times higher than the value of bare CuO (4.18%). The theoretical calculations reveal that energy barrier of HER on FeOOH/CuO/ZnO photocathode is dramatically reduced, greatly improving the catalytic activity for HER. This study highlights the crucial functions of solar PEC conversion and offers comprehensive insights into interfacial charge transfer in designing efficient photocathode materials.
光电化学（PEC）水还原为生成“绿色”氢气提供了一种很有前景的方法。光阴极上的析氢反应（HER）受到显著限制，主要是因为光生电子 - 空穴对的快速复合以及水分解步骤中遇到的高能量势垒。在此，通过水热和电沉积方法制备了一种独特的“三明治”结构FeOOH/CuO/ZnO复合光阴极。通过引入FeOOH作为空穴存储/传输层，光生生生空穴更容易从CuO提取并转移到FTO基板上。ZnO层作为电子转移剂，阻碍了电荷复合。因此，FeOOH/CuO/ZnO光阴极具有显著的PEC水还原能力。在0 V时，FeOOH/CuO/ZnO光阴极的最大光电流密度（-2.54 mA·cm²）比原始CuO（-0.2 mA·cm²）大12.7倍。FeOOH/CuO/ZnO的入射光电流转换效率（IPCE）达到33.7%（455 nm），比裸CuO的值（4.18%）高8.1倍。理论计算表明，FeOOH/CuO/ZnO光阴极上HER的能量势垒显著降低，大大提高了HER的催化活性。这项研究突出了太阳能PEC转换的关键作用，并为设计高效光阴极材料中的界面电荷转移提供了全面的见解。
