Liu Cailing, Ren Xiaohui, Sahoo Smruti Ranjan, Kuklin Artem, Yao Chen, Ågren Hans, Zhang Ye
School of Resources Environment and Safety Engineering, University of South China, Hengyang, 421001, P. R. China.
The State Key Laboratory of Refractories and Metallurgy, Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education & Hubei Provincial Key Laboratory for New Processes of Ironmaking and Steel making, Faculty of Materials, Wuhan University of Science and Technology, Wuhan, 430081, P. R. China.
Adv Sci (Weinh). 2025 Sep 12:e12163. doi: 10.1002/advs.202512163.
Efficient charge separation is critical for high-performance photocatalytic reduction of U(VI) in nuclear wastewater. Employing defect engineering, an oxygen vacancy (V)-enriched S-scheme ZnO-V@ZnCdS (ZnO-V@ZCS) heterojunction is constructed for rapid U(VI) removal. The synergistic effect of oxygen vacancies and the S-scheme mechanism is shown to significantly enhance charge separation and photocatalytic U(VI) reduction. Remarkably, ZnO-V@ZCS achieves 99.10% U(VI) removal within 10 min at pH 4 under simulated sunlight without sacrificial agents, surpassing the V-free ZnO@ZCS reference and exhibiting 4.10-fold and 20.0-fold higher activity than pristine ZnO-V and ZCS, respectively. Meanwhile, the catalyst maintains robust performance across a wide pH range (3-8), complex matrices (interfering ions/dyes), natural sunlight, and diverse U(VI) containing wastewater. In situ X-ray photoelectron spectroscopy (In situ XPS) and Kelvin probe force microscopy (KPFM) confirm the S-scheme charge transfer between ZnO-V and ZCS. Femtosecond transient absorption spectroscopy (fs-TAS) and density functional theory (DFT) calculations reveal that V serve as transient electron traps, creating rapid charge-transfer channels that interplay with the S-scheme to enhance charge transfer efficiency and accelerate U(VI) reduction kinetics. This study provides new insights for designing defect-modulated S-scheme heterojunction photocatalysts, promising for sustainable nuclear wastewater treatment.
高效的电荷分离对于核废水中U(VI)的高性能光催化还原至关重要。通过缺陷工程，构建了一种富含氧空位(V)的S型ZnO-V@ZnCdS(ZnO-V@ZCS)异质结用于快速去除U(VI)。结果表明，氧空位和S型机制的协同效应显著增强了电荷分离和光催化U(VI)还原。值得注意的是，在模拟太阳光下，pH为4时，ZnO-V@ZCS在无牺牲剂的情况下10分钟内实现了99.10%的U(VI)去除，超过了不含V的ZnO@ZCS参比样品，其活性分别比原始的ZnO-V和ZCS高4.10倍和20.0倍。同时，该催化剂在较宽的pH范围(3-8)、复杂基质(干扰离子/染料)、自然太阳光以及多种含U(VI)的废水条件下均保持稳定的性能。原位X射线光电子能谱(In situ XPS)和开尔文探针力显微镜(KPFM)证实了ZnO-V和ZCS之间的S型电荷转移。飞秒瞬态吸收光谱(fs-TAS)和密度泛函理论(DFT)计算表明，V作为瞬态电子陷阱，创建了快速电荷转移通道，与S型机制相互作用以提高电荷转移效率并加速U(VI)还原动力学。本研究为设计缺陷调制的S型异质结光催化剂提供了新的见解，有望用于可持续的核废水处理。
