In situ growth of ultrathin Co-MOF nanosheets on Α-Fe2O3 hematite nanorods for efficient photoelectrochemical water oxidation

Zhang, Qi; Wang, Hongyan; Dong, Yixin; Yan, Jitong; Ke, Xuebin; Wu, Quanping; Xue, Song

Abstract

Efficient charge transport is an important factor in photoelectrochemical (PEC) water splitting. The charge transfer at the semiconductor/electrolyte interface is of great importance, especially for the complex water oxidation reaction. In this study, we explored the feasibility of improving charge transfer efficiency at the interface of semiconductor/electrolyte by in situ growth of Co based Metal-Organic Frame work (Co-MOF) through a facile ion-exchanging method. Under optimized conditions, the Co-MOF nanosheet-modified hematite gave a photocurrent density of 2.0 mA cm−2 (200% improvement) at 1.23 VRHE with a cathodic shift of 180 mV in the photocurrent onset potential, in comparison to bare α-Fe2O3 (0.71 mA cm−2@1.23 VRHE). To elucidate the role of Co-MOF, X-ray photoelectron spectroscopy, electrochemical impedance spectroscopy and Mott-Schottky measurements were carried out. It was found that the atomically distributed Co2+ in Co-MOF possessed excellent hole storage capability and charge transfer efficiency, as evidenced by the high surface capacitance and extremely low surface charge transfer resistance.

Citation

Zhang, Q., Wang, H., Dong, Y., Yan, J., Ke, X., Wu, Q., & Xue, S. (2018). In situ growth of ultrathin Co-MOF nanosheets on Α-Fe2O3 hematite nanorods for efficient photoelectrochemical water oxidation. Solar Energy, 171, 388-396. https://doi.org/10.1016/j.solener.2018.06.086

• Journal Article Type: Article
• Acceptance Date: Jun 22, 2018
• Online Publication Date: Jul 2, 2018
• Publication Date: Sep 1, 2018
• Deposit Date: Sep 3, 2018
• Publicly Available Date: Jul 3, 2019
• Journal: Solar Energy
• Print ISSN: 0038-092X
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 171
• Pages: 388-396
• DOI: https://doi.org/10.1016/j.solener.2018.06.086
• Keywords: Hematite; Photoelectrochemical water splitting; Metal–organic framework; Photocurrent
• Public URL: https://hull-repository.worktribe.com/output/987720
• Publisher URL: https://www.sciencedirect.com/science/article/pii/S0038092X18306376?via%3Dihub
• Additional Information: This is the accepted manuscript of an article published in Solar energy, 2018. The version of record is available at the DOI link in this record.
• Contract Date: Jun 6, 2019