Wen Huan, Chen Shu, Zuo Jian, Zhang Jie, Liu Canjun, Liu Yang, Wang Keke, Chen Hezhang, Pei Yong
Key Laboratory of Theoretical Organic Chemistry and Function Molecule of Ministry of Education, School of Chemistry and Chemical Engineering, Hunan University of Science and Technology, Xiangtan 411201 Hunan, China.
Key Laboratory of Theoretical Organic Chemistry and Function Molecule of Ministry of Education, School of Chemistry and Chemical Engineering, Hunan University of Science and Technology, Xiangtan 411201 Hunan, China.
J Colloid Interface Sci. 2025 Nov 15;698:138030. doi: 10.1016/j.jcis.2025.138030. Epub 2025 May 29.
The primary challenge in enhancing the efficiency of solar energy conversion lies in improving the charge separation efficiency for photocatalytic (PC)/photoelectrochemical (PEC) processes, and the construction of heterojunctions represents one of the most effective strategies for promoting charge separation in the bulk phase. However, further investigation is necessary to elucidate the impact of the heterojunction interface structure on charge separation. In this paper, CdS/CdO and CdO/CdS films were prepared using an in-situ phase transformation approach to achieve a well-defined heterojunction interface structure for comparison. The research findings reveal significant disparities in the initiation potential and charge separation efficiency between CdS/CdO and CdO/CdS, with CdS/CdO exhibiting superior PEC properties. Notably, the photocurrent density of CdS/CdO reaches 6.5 mA cm at 1.23 V. This can be attributed to the fact that the favorable alignment of the built-in electric field (BEF) in CdS/CdO with the applied bias direction facilitates efficient charge separation and transmission at the heterojunction interface, as supported by the experimental results, density functional theory (DFT) calculations and finite element analysis (FEA). This finding offers a novel insight for the design and fabrication of high-performance heterojunction photocatalysts and photoelectrocatalysts.
提高太阳能转换效率的主要挑战在于提高光催化（PC）/光电化学（PEC）过程中的电荷分离效率，而构建异质结是促进体相中电荷分离的最有效策略之一。然而，有必要进一步研究以阐明异质结界面结构对电荷分离的影响。本文采用原位相变方法制备了CdS/CdO和CdO/CdS薄膜，以实现明确的异质结界面结构用于比较。研究结果表明，CdS/CdO和CdO/CdS之间的起始电位和电荷分离效率存在显著差异，CdS/CdO表现出优异的PEC性能。值得注意的是，CdS/CdO在1.23 V时的光电流密度达到6.5 mA/cm²。这可以归因于CdS/CdO中内建电场（BEF）与外加偏置方向的有利对齐，有利于在异质结界面处进行有效的电荷分离和传输，实验结果、密度泛函理论（DFT）计算和有限元分析（FEA）均支持这一点。这一发现为高性能异质结光催化剂和光电催化剂的设计与制备提供了新的见解。
