Abstract Designing low-cost and high-performance photoelectrodes with improved light harvesting and charge separation rates is significant in photoelectrochemical water splitting. Here, a novel TiO2/Cu2O/Al/Al2O3 photoelectrode is manufactured by depositing plasmonic nanoparticles of the non-noble metal Al on the surface of a TiO2/Cu2O core/shell heterojunction for the first time. The Al nanoparticles, which exhibit a surface plasmon resonance (SPR) effect and are substantially less expensive than noble metals such as Au and Ag, generate hot electron–hole pairs and amplify the electromagnetic field at the interface under illumination. The as-prepared TiO2/Cu2O/Al/Al2O3 photoelectrodes have an extended absorption range and enhanced carrier separation and transfer. Their photocurrent density of 4.52 mA·cm−2 at 1.23 V vs. RHE represents an 1.84-fold improvement over that of TiO2/Cu2O. Specifically, the ultrathin Al2O3 passivation layer spontaneously generated on the surface of Al in air could act as a protective layer to significantly increase its stability. In this work, the synergistic effect of the heterojunctions and the SPR effect of the non-noble metal Al significantly improve the photoelectrode performance, providing a novel concept for the design of electrodes with good properties and high practicability.

中文翻译：

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在 TiO2/Cu2O 光阳极上装饰非贵金属等离子体 Al 以提高光电化学水分解性能

摘要 设计具有改进的光收集和电荷分离率的低成本和高性能光电极在光电化学水分解中具有重要意义。在这里，通过在 TiO2/Cu2O 核/壳异质结的表面上沉积非贵金属 Al 的等离子体纳米粒子，制造了一种新型的 TiO2/Cu2O/Al/Al2O3 光电极。铝纳米粒子表现出表面等离子体共振 (SPR) 效应，并且比金和银等贵金属便宜得多，可产生热电子 - 空穴对并在光照下放大界面处的电磁场。所制备的 TiO2/Cu2O/Al/Al2O3 光电极具有扩展的吸收范围和增强的载流子分离和转移。它们在 1.23 V 与 RHE 下的光电流密度为 4.52 mA·cm-2，代表 1。比 TiO2/Cu2O 提高 84 倍。具体而言，空气中Al表面自发产生的超薄Al2O3钝化层可以作为保护层，显着提高其稳定性。在这项工作中，异质结的协同效应和非贵金属Al的SPR效应显着提高了光电极的性能，为具有良好性能和实用性的电极设计提供了一个新的概念。