Zhang Yifeng, Sun Haorong, Gao Feixue, Zhang Shuo, Han Qingzhi, Li Jing, Fang Ming, Cai Yawen, Hu Baowei, Tan Xiaoli, Wang Xiangke
MOE Key Laboratory of Resources and Environmental System Optimization, College of Environmental Science and Engineering, North China Electric Power University, Beijing 102206, China.
Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, China.
Research (Wash D C). 2022 Oct 11;2022:9790320. doi: 10.34133/2022/9790320. eCollection 2022.
In this work, a CdS/BiVO step-scheme (S-scheme) heterojunction with self-photothermally enhanced photocatalytic effect was synthesized and applied for efficient U(VI) photoextraction. Characterizations such as transient absorption spectroscopy and Tafel test together confirmed the formation of S-scheme heterojunctions, which allows CdS/BiVO to avoid photocorrosion while retaining the strong reducing capacity of CdS and the oxidizing capacity of BiVO. Experimental results such as radical quenching experiments and electron spin resonance show that U(VI) is rapidly oxidized by photoholes/OH to insoluble UO(OH) after being reduced to U(IV) by photoelectrons/O , which precisely avoids the depletion of electron sacrificial agents. The rapid recombination of electron-hole pairs triggered by the S-scheme heterojunction is found to release large amounts of heat and accelerate the photocatalysis. This work offers a new enhanced strategy for photocatalytic uranium extraction and presents a direction for the design and development of new photocatalysts.
在这项工作中，合成了具有自光热增强光催化效应的CdS/BiVO分步方案（S型）异质结，并将其应用于高效的U(VI)光萃取。瞬态吸收光谱和塔菲尔测试等表征共同证实了S型异质结的形成，这使得CdS/BiVO在避免光腐蚀的同时，保留了CdS的强还原能力和BiVO的氧化能力。自由基猝灭实验和电子自旋共振等实验结果表明，U(VI)在被光电子/O还原为U(IV)后，被光生空穴/OH迅速氧化为不溶性的UO(OH)，这恰好避免了电子牺牲剂的消耗。发现由S型异质结引发的电子-空穴对的快速复合会释放大量热量并加速光催化。这项工作为光催化铀萃取提供了一种新的增强策略，并为新型光催化剂的设计和开发提供了一个方向。
