Deposition of g-C₃N₄ onto Three-Dimensional Porous Carbon for Photocatalytic Reduction of U(VI)

A 3D PC/g-C₃N₄ composite photocatalyst was fabricated by impregnating three-dimensional porous carbon (3D PC)—possessing an extended π-conjugated network—into melamine followed by thermal polycondensation. The resulting architecture exhibits a curved, cage-like 3D morphology, enlarged specific surface area and markedly suppressed recombination of photogenerated charge carriers. Owing to its superior electrical conductivity, the incorporated 3D PC serves as an electron-transfer highway that efficiently shuttles photogenerated electrons and thus dramatically enhances the photocatalytic reduction of U(VI). Under optimized conditions, the 20 wt % 3D PC/g-C₃N₄ composite achieves 90.6% removal of U(VI) within 100 min of visible-light irradiation, corresponding to a reaction rate 4.4-fold higher than that of bulk g-C₃N₄. The composite also demonstrates excellent recyclability and structural stability across repeated cycles.