Piezoelectric Effect-Mediating Reactive Oxygen Species in NiTiO<sub>3</sub> Nanorods for Photocatalytic Removal of U(VI)
Junjie Chen, Yaoxuan Wang, Dongling Zeng, Zifan Li, Haonan Pei, Xiaohong Cao, Youqun Wang, Zhimin Dong, Zhibin Zhang, Yunhai Liu
Abstract
Piezoelectric catalysis could convert mechanical energy into chemical energy, which can combine with solar energy for a high-efficiency piezo-photocatalysis reaction. In this work, NiTiO 3 nanorods were synthesized via the sol–gel method and initially employed for the removal of U(VI) from radioactive-contaminated water. The NiTiO 3 nanorods will generate an internal electric field in an ultrasonic environment, which could greatly improve the performance of piezo-photocatalysis in reducing U(VI) by promoting the generation of photoexcited electrons and reactive oxygen species (ROS). After exposure to visible light and ultrasound for 3 h, the NTO-R-1 exhibited superb U(VI) degradation efficiency of 93.91%, which was 2.58, 6.15, and 6.68 times greater than those of visible light, ultrasonic irradiation, and dark, respectively. Moreover, photoexcited electrons and oxygen-active species play a decisive role in the piezo-photocatalysis process. Therefore, NiTiO 3 with excellent piezo-photocatalysis properties exhibits good potential for the development of efficient wastewater purification catalysts and also helps to probe the possible mechanism of piezo-photocatalysis removal of U(VI) in wastewater.