High-efficient U(VI) removal from organic wastewater through polarization electric field enhanced photocatalysis with In2Se3@Ag3PO4 heterojunction

Abstract

Effective catalytic methods and catalysts for the simultaneous removal of coexisting organic pollutants and heavy metal ions are crucial for sustainable and environmentally friendly water purification. Herein, flower-like S-scheme In2Se3@Ag3PO4 heterojunctions were synthesized by a two-step hydrothermal method for simultaneous removal of uranium (VI) (U(VI)) and organic pollutants using piezo-photocatalysis. Characterization and theoretical calculations confirmed the formation of the heterojunction, highlighting the significance of InO and SeP bonds in the S-scheme for enhancing photocatalytic reactions by improving charge carrier separation and migration. Additionally, the piezoelectric polarization electric field can also improve photocatalytic performance. The optimized In2Se3@Ag3PO4–3 catalyst demonstrated superior piezo-photocatalytic performance in synergistically removing U(VI) and degrading organics, such as tetracycline (TC), bisphenol A (BPA), carbamazepine (CBZ), levofloxacin (LVX), and norfloxacin (NOR). Particularly, in the presence of TC, the catalyst achieved 98.7 % U(VI) removal, and 94.1 % TC degradation within 30 min. This study introduces a promising strategy and a novel heterojunction catalyst with dual functional properties for the simultaneous treatment of wastewater containing organic pollutants and U(VI).