Revealing the charge transfer mechanism and assessing product toxicity in the 2D/1D BiOCO/Bi(CrO)O heterostructure system

With improved charge separation efficiency, heterojunction catalysts are widely used to enhance photocatalytic activity. However, the transfer mechanism of photoexcited charge carriers remains unclear. In this work, we report for the first time on the use of the type I heterojunction, Bi 2 O 2 CO 3...

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Published inEnvironmental science. Nano Vol. 1; no. 7; pp. 1867 - 1882
Main Authors Yang, Yang, Gu, Xiaomeng, Gong, Kexin, Meng, Sugang, Lei, Jian, Zheng, Xiuzhen, Feng, Yiqing, Chen, Shifu
Format Journal Article
Published 13.07.2023
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Summary:With improved charge separation efficiency, heterojunction catalysts are widely used to enhance photocatalytic activity. However, the transfer mechanism of photoexcited charge carriers remains unclear. In this work, we report for the first time on the use of the type I heterojunction, Bi 2 O 2 CO 3 /Bi 8 (CrO 4 )O 11 , with varying mass ratios for water purification and explore the mechanism of charge transfer. The 20% Bi 2 O 2 CO 3 /Bi 8 (CrO 4 )O 11 heterojunction showed the highest photocatalytic activities for the degradation of typical dyes and antibiotics, including bisphenol A (BPA), methylene blue (MB), rhodamine B (RhB), methyl orange (MO) and tetracycline (TC). The BPA photodegradation rate was 2.37 and 8.83 times higher than those of Bi 8 (CrO 4 )O 11 and Bi 2 O 2 CO 3 , respectively. The results demonstrate that the internal electric field between Bi 2 O 2 CO 3 and Bi 8 (CrO 4 )O 11 can significantly boost the photocatalytic efficiency through highly promoted separation of electron-hole pairs by forming the S-scheme heterojunction. The trapping experiments and electron paramagnetic resonance (EPR) results indicate that hydroxyl radicals, holes and superoxide radicals all act as active species in the Bi 2 O 2 CO 3 /Bi 8 (CrO 4 )O 11 heterojunction, efficiently extending the practical application of photocatalysts. The possible photodegradation pathways of MB and BPA were proposed based on the results of liquid chromatography-mass spectrometry (LC-MS). Furthermore, we verified that BPA solutions treated with Bi 2 O 2 CO 3 /Bi 8 (CrO 4 )O 11 heterojunctions are harmless for wheat seed germination. The 2D/1D Bi 2 O 2 CO 3 /Bi 8 (CrO 4 )O 11 photocatalysts displayed great potential as an environmentally friendly strategy for wastewater purification. The type I heterojunction Bi 2 O 2 CO 3 /Bi 8 (CrO 4 )O 11 exhibits high activity and stability for photocatalytic degradation of various organic pollutants.
Bibliography:https://doi.org/10.1039/d3en00112a
Electronic supplementary information (ESI) available. See DOI
ISSN:2051-8153
2051-8161
DOI:10.1039/d3en00112a