Highly efficient bi-metallic bismuth-silver doped TiO2 photocatalyst for dye degradation

Several mono-and bi-metallic photocatalysts with different loadings have been synthesized using ultrasound assisted sol gel and wet impregnation methods. Synthesized catalysts were characterized using various analytical techniques to determine the bandgap, functional groups, crystallinity, and surface morphology. Photocatalytic performance of the different catalysts was compared in terms of Rhodamine-B dye degradation, and further process optimization studies were carried out to achieve the maximum extent of degradation. Catalyst performance was studied both under UV and visible light irradiation for the degradation of different dyes. Compared to pure TiO2 and monometallic Ag or Bi doped on TiO2, bi-metallic Bi-Ag on TiO2 catalyst synthesized using wet impregnation was found to be highly active under the conditions investigated. Complete degradation (∼100%) was obtained within shorter duration in the presence of minimal catalyst loading (60 mg/L). Overall, this work has clearly demonstrated the higher catalytic activity of bi-metallic catalyst, which is attributed to the synergistic effect of Bi and Ag on TiO2 facilitating the efficient charge separation and improved e− transfer combined with high ability to absorb in visible light region in effectively degrading organic pollutants.