Visible-light-active Ag-doped BiVO4 nanostructures: Preparation and optical and photocatalytic studies

Ag-doped bismuth vanadate (Ag-BiVO₄) nanostructures were successfully fabricated using the hydrothermal method. The effect of Ag doping was studied on the microstructural, optical, and visible-light-active photocatalytic degradation properties. Optical analysis confirmed the enhancement of the visible light absorption ability and the reduction of bandgap energy due to Ag incorporation into the crystalline lattice of BiVO₄. Ag-doped BiVO₄ catalysts exhibited significantly higher visible-light photocatalytic response compared to the Un-doped BiVO₄ sample, indicating improved separation of photoexcited excitons. Ag-doped BiVO₄ photocatalysts showed the best performance for the Ag-BiVO₄-2 sample, with a degradation efficiency of 95.17 % at a pseudo-first-order kinetic constant of 0.019 min⁻¹, 1.35 times higher than that of the Un-doped BiVO₄ sample. This result suggests that the decreased bandgap energy of BiVO₄ may be responsible for the enhanced photocatalytic activity. A possible photocatalytic mechanism for methylene blue degradation over Ag-doped BiVO₄ was also discussed.