Band alignment engineering for improved performance and stability of ZnFe2O4 modified CdS/ZnO nanostructured photoanode for PEC water splitting

• Published in: Nano energy 2016-06, Vol.24, p.25-31
• Main Authors: Cao, Shiyao, Yan, Xiaoqin, Kang, Zhuo, Liang, Qijie, Liao, Xinqin, Zhang, Yue
• Format: Article
• Language: English
• Subjects: Core/shell; Photoelectrochemical; Stability; ZnFe2O4
• ISSN: 2211-2855
• DOI: 10.1016/j.nanoen.2016.04.001

ZnFe2O4 modified CdS quantum dots/ZnO nanorods core/shell structured photoanode has been designed and successfully fabricated. With the decoration of ZnFe2O4, both the photoelectrochemical performance and the stability of the CdS/ZnO photoanode were enhanced. The improved photoelectrochemical performance can be attributed to the typical stair-like type-II band alignment between ZnFe2O4, CdS and ZnO. The heterojunction between ZnFe2O4, CdS and ZnO can enhance the separation efficiency of the charge carriers. In addition, ZnFe2O4 nanoparticles can serve as holes receptor of CdS and act as a protective layer which will reduce the photocorrosion of CdS and improve the stability of the photoanode. The optimized photoanode exhibited a remarkable solar-to-hydrogen efficiency of 4.4% which was 15.7 times than that of the pristine ZnO photoanode. This work provides a strategy for designing and fabricating stable and efficient photoanode. ZnFe2O4 modified CdS quantum dots/ZnO nanorods core/shell structured photoanode has been designed and successfully fabricated. The light absorption has been extended to visible light after the decoration of CdS and ZnFe2O4. The instability of the CdS quantum dots was addressed by the decoration of ZnFe2O4 and the performance of the photoelectrochemical cell improved simultaneously. This work provides a strategy for designing and fabricating stable photoanode in electrolyte with a high efficiency. [Display omitted] •A ZnFe2O4 modified CdS quantum dots/ZnO nanorods core/shell structured photoanode has been designed and successfully fabricated.•The structure integrates the motif of quantum dot sensitization and band alignment engineering to simultaneously enhance the visible light absorption and carrier separation efficiency.•The optimized photoanode exhibited a remarkable solar-to-hydrogen efficiency of 4.4%.•The optimized photoanode shows improved stability with 85.1% of the initial photocurrent retained after 1h irradiation.