Developing a highly efficient visible-light-driven TiO₂-based photocatalyst for the degradation of tetracycline remains challenging due to the high photogenerated electron/hole recombination rate and narrow visible light response range of TiO₂. To address these problems, novel heterojunctions are fabricated by coupling TiO₂ nanosheets with Mn_0.5Cd_0.5S nanoparticles as visible-light photocatalysts. The as-synthesized photocatalysts exhibit high photogenerated electron/hole separation efficiency and enhanced visible-light absorption due to the well-matched energy levels, leading to the highly efficient degradation of tetracycline under visible light irradiation and excellent recyclability. The degradation efficiency of the optimum MCS/TiO₂-II photocatalyst could reach 90% within 120 min, which was about 2.5 times and 6.9 times higher than those of MCS and TiO₂, respectively. Furthermore, the degradation mechanism of tetracycline was revealed in depth based on the trapping experiments, XPS, photoelectrochemical characterizations, and DFT calculations. Therefore, this work provides an effective approach to explore excellent photocatalysts to realize the highly efficient removal of refractory tetracycline under visible light.

中文翻译：

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简便的原位构建策略，将 Mn0.5Cd0.5S 纳米颗粒沉积在 TiO2 纳米片上，用于高效可见光催化降解四环素


由于TiO ₂的高光生电子/空穴复合率和窄的可见光响应范围，开发用于降解四环素的高效可见光驱动的TiO ₂基光催化剂仍然具有挑战性。为了解决这些问题，通过将TiO ₂纳米片与作为可见光光催化剂的Mn _0.5 Cd _0.5 S纳米粒子偶联来制备新型异质结。由于能级匹配良好，所合成的光催化剂表现出高光生电子/空穴分离效率和增强的可见光吸收，从而在可见光照射下高效降解四环素，并具有优异的可回收性。最佳MCS/TiO ₂ -II光催化剂的降解效率可在120 min内达到90%，分别是MCS和TiO ₂的2.5倍和6.9倍。此外，基于捕获实验、XPS、光电化学表征和DFT计算，深入揭示了四环素的降解机制。因此，本工作为探索优异的光催化剂以实现可见光下难降解四环素的高效去除提供了有效途径。