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.