Currently, upconversion nanoparticles (UCNPs) based photocatalysts have been extensively developed to improve solar energy utilization. However, the mechanisms underlying interfacial energy migration of upconversion photocatalyst remain unclear. Herein, a promising composite photocatalyst with complementary properties is designed by integrating -NaGdF:Yb/Er (NGFYE), CdS and multi-walled carbon nanotubes (MWCNTs). The morphology, structure and chemical properties of NGFYE@CdS/MWCNTs ternary photocatalyst are characterized. In addition, the existence of Förster resonance energy transfer process in NGFYE@CdS/MWCNTs photocatalysts, i.e., the migration of excitation energy from Er−S excitation level and higher excitation level (e.g., Er−H) to CdS nanoparticles, was further confirmed by density functional theory (DFT) calculations. The optimized NGFYE@CdS/MWCNTs photocatalyst presents 71.65 % and 35.29 % degradation of tetracycline hydrochloride (TCH) and ciprofloxacin (CIP) under λ ≥ 800 nm irradiation for 3 h, respectively. This work not only illustrates the interfacial energy migration mechanism between NGFYE and CdS, but also provides insights for the rapid construction of heterojunction materials with efficient energy transfer interfaces.

中文翻译：

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β-NaGdF4:Yb,Er@CdS/MWCNTs 光催化剂具有高效的界面能量迁移，可实现全光谱光驱动的抗生素降解：构建和 DFT 见解


目前，基于上转换纳米粒子（UCNP）的光催化剂已被广泛开发以提高太阳能利用率。然而，上转换光催化剂界面能量迁移的机制仍不清楚。在此，通过整合-NaGdF:Yb/Er（NGFYE）、CdS和多壁碳纳米管（MWCNT）设计了一种具有互补特性的有前景的复合光催化剂。对NGFYE@CdS/MWCNTs三元光催化剂的形貌、结构和化学性质进行了表征。此外，进一步证实了NGFYE@CdS/MWCNTs光催化剂中存在Förster共振能量转移过程，即激发能从Er−S激发能级和更高激发能级（例如Er−H）向CdS纳米颗粒的迁移通过密度泛函理论（DFT）计算。优化的 NGFYE@CdS/MWCNTs 光催化剂在 λ ≥ 800 nm 照射 3 小时下，盐酸四环素 (TCH) 和环丙沙星 (CIP) 的降解率分别为 71.65% 和 35.29%。这项工作不仅阐明了NGFYE和CdS之间的界面能量迁移机制，而且为快速构建具有高效能量传输界面的异质结材料提供了见解。