Controlled synthesis of bifunctional 3D BiOBr:Eu 3+ hierarchitectures with tunable thickness for enhanced visible light photocatalytic activities and mechanism insight

• Published in: Catalysis science & technology Vol. 9; no. 18; pp. 5011 - 5021
• Main Authors: Li, Yongjin, Yao, Lu, Cheng, Zhiyuan, Yang, Shenghong, Zhang, Yueli
• Format: Journal Article
• Language: English
• Published: 24.09.2019
• ISSN: 2044-4753; 2044-4761
• DOI: 10.1039/C9CY00946A

In this work, bifunctional 3D BiOBr:Eu 3+ hierarchical nanostructures (HNs) assembled from 2D nanosheets with adjustable thickness were successfully fabricated via a solvothermal method by altering the amount of sodium citrate. The addition of sodium citrate effectively reduced the thickness of self-assembled nanosheets from 56 nm to 25 nm. The effects of thickness on the photoluminescence (PL) and photocatalytic activities of BiOBr:Eu 3+ HNs had been systematically investigated. The results showed that the red emission of Eu 3+ and the photocatalytic efficiency in degradation of MB were both improved significantly as the thickness of the nanosheets decreased. Upon excitation with blue light (465 nm), the BiOBr:Eu 3+ HNs exhibited intense red emission corresponding to the 5 D 0 → 7 F 2 transitions of Eu 3+ ions. Structural insights into the PL of Eu 3+ ions revealed that the internal electric field (IEF) in BiOBr HNs increased significantly with decreasing sheet thickness, which improved the excitation field of Eu 3+ ions and favored photogenerated charge separation and transfer. This work not only provided a new thought for understanding the photoreactivity through dopant PL, but also provided a platform for fabricating multifunctional materials for environmental and energy conversion applications.