LSPR-enhanced photocatalytic reduction of U(VI) over Pt quantum dots decorated g-C 3 N 4 nanosheets under visible light

Visible-light-driven photocatalysis has emerged as a promising approach for the efficient removal of U(VI) from wastewater. In this work, Pt quantum dots (PQD) were synthesized via NaBH ₄ reduction and subsequently anchored onto g-C ₃ N ₄ nanosheets (CNs) to fabricate PQD _n -CNs composite photocatalysts (where n denotes the mass fraction of PQD), aiming to enhance the photocatalytic activity of pristine CNs. The morphology, chemical composition and optical properties of PQD _n -CNs composites were systematically characterized using various techniques. Notably, PQD ₃ -CNs exhibited 97.9% U(VI) removal efficiency within 150 min of visible light irradiation, representing a 2.45-fold enhancement compared to bare CNs. Furthermore, PQD ₃ -CNs demonstrated excellent stability and recyclability over five cycles. Mechanistically, radical scavenging experiments revealed that photogenerated electron (e ⁻ ) and superoxide radicals (•O ₂ ⁻ ) synergistically facilitated U(VI) reduction, elucidating the underlying photocatalytic pathway. Overall, the PQDₙ-CNs photocatalyst holds promise for providing novel insights into the treatment of radionuclide-contaminated wastewater.