Piezo-catalysis in BiFeO₃@In₂Se₃ Heterojunction for High-Efficiency Uranium Removal

Piezo-catalysis emerges as an efficient, safe, and affordable strategy for removing hazardous substances from aquatic environments. Here, the BiFeO₃@In₂Se₃ heterojunction demonstrates remarkable prowess as a piezo-catalyst, enabling the high-efficiency removal of uranium (U) from U(VI)-containing water. A total U(VI) removal efficiency of 94.6% can be achieved under ultrasonic vibration without any sacrificial agents. During the entire catalytic process, piezo-induced electrons, hydroxyl radicals, and superoxide radicals play important roles in U(VI) removal, while the generated H₂O₂ is responsive to the transformation of soluble U(VI) into insoluble (UO₂)O₂•2H₂O and UO₃. Furthermore, auxiliary illumination can accelerate the increase of free charges, enabling the piezo-catalyst to retain more charges. This leads to an improved U(VI) removal efficiency of 98.8% and a significantly increased reaction rate constant. This study offers a comprehensive analysis of the fabrication of high-efficiency piezo-catalysts in the removal or extraction of U(VI) from U(VI)-containing water.