Two-Dimensional Lamellar Stacked Bi<sub>2</sub>O<sub>3</sub>/CeO<sub>2</sub> Type-II Heterojunctions Promote Carrier Separation to Enhance Ciprofloxacin Oxidation
The development of efficient and stable photocatalysts is critical for addressing water pollution challenges caused by persistent organic contaminants. However, single-component photocatalysts often suffer from rapid photogenerated carrier recombination and limited visible-light absorption. In this...
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| Main Authors: | , , , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2025-04-01
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| Series: | Reactions |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2624-781X/6/2/29 |
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| Summary: | The development of efficient and stable photocatalysts is critical for addressing water pollution challenges caused by persistent organic contaminants. However, single-component photocatalysts often suffer from rapid photogenerated carrier recombination and limited visible-light absorption. In this study, a two-dimensional lamellar stacked Bi<sub>2</sub>O<sub>3</sub>/CeO<sub>2</sub> type-II heterojunction photocatalyst (BC) was successfully synthesized in situ by a topological transformation strategy induced by high-temperature oxidation of monolithic Bi. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) analyses confirmed the uniform distribution of Bi<sub>2</sub>O<sub>3</sub> nanosheets on CeO<sub>2</sub> surfaces, forming an intimate interfacial contact that enhances charge separation and transfer efficiency. Photoluminescence (PL) spectroscopy, UV–visible diffuse reflectance spectroscopy (DRS), and electrochemical characterization revealed extended visible-light absorption (up to 550 nm) and accelerated electron migration in the heterojunction. Under simulated sunlight, the optimized BOC (3:1) composite exhibited a ciprofloxacin (CIP) degradation rate constant 2.30 and 5.63 times higher than pure Bi<sub>2</sub>O<sub>3</sub> and CeO<sub>2</sub>, respectively. Theoretical calculations validated the type-II band alignment with conduction and valence band offsets of 0.07 eV and 0.17 eV, which facilitated efficient spatial separation of photogenerated carriers. This work provides a rational strategy for designing heterojunction photocatalysts and advancing their application in water purification. |
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| ISSN: | 2624-781X |