Huang Yu-Hao, Chuang Yung-Tang, Lin Hao-Wu, Liao Chien-Neng
College of Semiconductor Research, National Tsing Hua University, Hsinchu 30013, Taiwan.
Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan.
Inorg Chem. 2025 Aug 25;64(33):16950-16959. doi: 10.1021/acs.inorgchem.5c02573. Epub 2025 Aug 12.
Cuprous oxide (CuO) is a promising material for photoelectrochemical water splitting due to its favorable band structure, environmental acceptability, nontoxicity, and ease of fabrication. In this study, (111)-textured CuO films decorated with numerous ZnO nanoparticles (NPs), namely ZCO films, are synthesized by a facile one-step electrodeposition method. The mechanism for forming ZnO NPs during the electrodeposition of CuO films is proposed. Based on the Mott-Schottky analysis and electrochemical impedance spectroscopy measurements, the presence of ZnO NPs on the CuO films enhances band bending and reduces charge transfer resistance to the electrolyte, which is advantageous for separating photoexcited electron and hole carriers in the illuminated ZCO films. Additionally, excess oxygen vacancy defects may facilitate the interdefect hopping of photoelectrons by minimizing the recombination probability of transporting photocarriers within the ZCO films according to photoluminescence spectroscopy analysis. The ZCO film exhibits a 40% increase in photocurrent density over the pristine CuO film in 1 M NaSO solution under AM1.5G illumination. This study provides a facile synthesis route for creating high-performance CuO-based photocathodes through heterojunction and crystal defect engineering.
氧化亚铜（CuO）因其良好的能带结构、环境可接受性、无毒且易于制备，是一种用于光电化学水分解的很有前景的材料。在本研究中，通过一种简便的一步电沉积法合成了装饰有大量氧化锌纳米颗粒（NPs）的（111）织构CuO薄膜，即ZCO薄膜。提出了在CuO薄膜电沉积过程中形成ZnO NPs的机制。基于莫特 - 肖特基分析和电化学阻抗谱测量，CuO薄膜上ZnO NPs的存在增强了能带弯曲并降低了对电解质的电荷转移电阻，这有利于在光照的ZCO薄膜中分离光激发的电子和空穴载流子。此外，根据光致发光光谱分析，过量的氧空位缺陷可通过最小化ZCO薄膜内传输光载流子的复合概率来促进光电子的缺陷间跳跃。在AM1.5G光照下，ZCO薄膜在1 M NaSO溶液中的光电流密度比原始CuO薄膜增加了40％。本研究通过异质结和晶体缺陷工程为制备高性能CuO基光阴极提供了一种简便的合成途径。
