Biosynthesis of highly porous Ag/Bi/SnO2 nanohybrid material using seeds extract of Caesalpinia bonduc and their photocatalytic activity

In the current study, Tin oxide (SnO2), Silver–Tin oxide (Ag–SnO2), and Ag–Bi–SnO2 nanoparticles (NPs) were successfully synthesized using methanolic seed extracts of Caesalpinia bonduc (C.bonduc) plants. The NPS were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), Surface area analysis (SAA), energy dispersive X-ray (EDX) analysis, and Fourier transmission infrared (FTIR). The synthesized photocatalyst's surface area was 210, 235, and 238 m2/g for SnO2 and Ag–SnO2, and Ag–Bi–SnO2, respectively. The catalyst showed excellent activity for the degradation of MB dye in an aqueous medium. The results confirmed that the Ag–Bi–SnO2 exhibited 94% degradation of dye compared to Ag–SnO2 (90%) and SnO2(80%) under the same reaction conditions. Adding Ag and bismuth can also increase the degradation mechanism by preventing recombining electron-hole pairs. The report is novel, as no report to date has been published for the synthesis of Ag–Bi–SnO2, Ag–SnO2, and SnO2 NPs synthesized by C. bonduc seed extract; the procedure is simple, cheaper, and non-toxic compared to other methods employed for the synthesis of NPs. Eley-Rideal (ER) type of reaction mechanism was found to follow the degradation of MB dye in an aqueous medium.