Construction of ZnO/CdS three-dimensional hierarchical photoelectrode for improved photoelectrochemical performance

• Published in: Renewable energy Vol. 153; pp. 241 - 248
• Main Authors: Xu, Shenming, Jiang, Jiangang, Ren, Wenyi, Wang, He, Zhang, Rui, Xie, Yingge, Chen, Yubin
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.06.2020
• Subjects: Heterojunction; Morphology tuning; Photoelectrochemical; Three-dimensional structure; Three-dimensional structure; Photoelectrochemical; Morphology tuning; Heterojunction
• ISSN: 0960-1481; 1879-0682
• DOI: 10.1016/j.renene.2020.02.001

Three-dimensional ZnO/CdS hierarchical films with uniform CdS deposition on the ZnO nanorods surface is prepared by a two-step hydrothermal method. The morphology of CdS nanostructure can be adjusted from particles to sheets and then blocks by changing amount of the surfactant in the precursor solution. The ZnO/CdS hierarchical film as photoelectrode with optimized morphology shows significant enhancement to the light harvesting and photoelectrochemical performance. Under light irradiation of 100 mW/cm2, the three-dimensional ZnO/CdS hierarchical film yields a photocurrent density of 4.5 mA/cm2, approximately two times higher than that of film without three-dimensional structure. The photoelectrochemical property improvement is attributed to the (1) enhanced light absorption due to the multi-scattering and multi-reflection of the unique three-dimensional hierarchical structure, (2) improved photogenerated carrier separation and transportation because of the hierarchical and heterojunction structure, and (3) facilitated hole transfer and reaction at the photoelectrode-electrolyte interface due to the large surface area. •Sheet-like CdS-Sensitized ZnO hierarchical film was synthesized via hydrothermal method.•Three dimensional ZnO/CdS hierarchical photoelectrode showed improvement PEC performance.•The possible charge transportation and separation mechanism was proposed.