A new 2D/2D heterojunction of MoS₂/CeO₂ is successfully prepared by a facile hydrothermal method. The MoS₂/CeO₂ heterojunction demonstrates superior photocatalytic performance for the degradation of ciprofloxacin (CIP) to that of pure MoS₂ and CeO₂. The enhanced degradation efficiency of the MoS₂/CeO₂ heterojunction is on account of the 2D/2D structure, which not only accelerates the interfacial charge separation but also endows the heterojunction with numerous reactive sites to facilitate the degradation reaction. Meanwhile, the Ce⁴⁺ ions in 2D CeO₂ serve as the redox centers and utilize the photogenerated carriers to generate more oxygen vacancies. In addition, this paper also carefully discusses the possible photocatalytic reaction mechanisms for the transfer behaviors of charge carriers, generation of reactive species and intermediate degradation products by electrochemical impedance spectroscopy (EIS), electron spin resonance (ESR) and HPLC-MS analysis. This work may provide a promising approach for synthesizing 2D/2D heterojunctions in photocatalytic degradation.

中文翻译：

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通过在2D-MoS2纳米片上修饰2D-CeO2构造的异质结光催化剂，具有增强的降解活性

通过简便的水热法成功地制备了MoS ₂ / CeO _2的2D / 2D异质结。与纯MoS ₂和CeO _2相比，MoS ₂ / CeO ₂异质结对环丙沙星（CIP）的降解具有优异的光催化性能。MoS ₂ / CeO ₂异质结的降解效率提高归因于2D / 2D结构，它不仅加速了界面电荷的分离，而且赋予异质结许多反应性位点，从而促进了降解反应。同时，二维CeO _2中的Ce ⁴⁺离子充当氧化还原中心，并利用光生载流子产生更多的氧空位。此外，本文还通过电化学阻抗谱（EIS），电子自旋共振（ESR）和HPLC-MS分析，仔细讨论了可能的光催化反应机理，用于电荷载流子的转移行为，反应性物种的产生和中间降解产物的产生。这项工作可能为合成光催化降解中的2D / 2D异质结提供有前途的方法。