Decoration of Ag/Bi nanoparticles over brown TiO_2-x/AgBiO₃ nanocomposites: QDs-sized photocatalysts for impressive mitigation of water pollutants

Heterogeneous photocatalysis is a hot-spot research field for energy conversion and water detoxification. One of the most important challenges of photocatalysis is the designing and development of efficacious visible-light-triggered photocatalysts. In this regard, perovskite AgBiO₃ and Ag/Bi elemental nanoparticles were decorated on brown TiO_2−x via a facile procedure. Electron microscopy, XPS, and XRD studies provided strong evidence about developing TiO_2−x/Ag/AgBiO₃/Bi photocatalysts with quantum dot size of about 5.5 nm, and intimate contact among the counterparts. The TiO_2−x/Ag/AgBiO₃/Bi photocatalysts displayed boosted ability in the detoxification of tetracycline (TC), amoxicillin (AMX), fuchsine (FS), and methylene orange (MO) pollutants. The degradation rate constants of TC, AMX, FS, and MO over the optimum TiO_2−x/Ag/AgBiO₃/Bi photocatalyst were 25.9, 3.40, 5.70, and 1.92 folds greater than TiO_2−x and 20.3, 12.3, 6.77, and 2.33 times larger than Ag/AgBiO₃/Bi, respectively. Photoluminescence spectroscopy, EIS experiments, and Bode plots showed accelerated charge transfer and significant reduction of charges recombination within TiO_2−x/Ag/AgBiO₃/Bi nanocomposites. The recycling studies showed that the plasmonic photocatalyst retained the most activity after four times of utilization. Ultimately, an s-scheme charges segregation route was suggested for the boosted activity of the plasmonic TiO_2−x/Ag/AgBiO₃/Bi photocatalysts.