Silver nanoparticle-decorated nanorod bismuth based -organic framework/graphitic carbon nitride composite for enhanced reactive blue 19 degradation under visible light

The Ag/UU-200@g-C 3 N 4 composite exhibited excellent photocatalytic performance for the degradation of RB19 dye under visible light. The characterizations of materials were confirmed by XRD, FT-IR, UV-Vis DRS, SEM, TEM, EDX, and XPS analyses. The composite demonstrated enhanced visible-light absorption and a reduced bandgap of 2.41 eV. The photocatalytic efficiency was optimized by tuning parameters such as NaBH 4 concentration, catalyst loading, dye concentration, and pH value. The unique electronic structure of g-C 3 N 4 , attributed to its nitrogen bonds and species—particularly the C–N = C bonds and tertiary nitrogen groups—facilitates effective charge separation. The proposed mechanism involves the generation of reactive oxygen species, primarily O 2 • − , as the main active species during degradation. The Ag/UU-200@g-C 3 N 4 catalyst exhibited notable stability and reusability, maintaining its efficacy over multiple cycles.