Photocatalytic properties of composites based on Y$_{1-x}$Bi$_x$FeO$_3$ (0$\le x\le$ 0.15) nanocrystalline solid solutions with a hexagonal structure

Nanopowders of Y$_{1-x}$Bi$_x$FeO$_3$ ($x$ = 0, 0.05, 0.10, 0.15) solid solutions were obtained by coprecipitation of hydroxides with simultaneous sonication and subsequent thermal treatment of the precipitate in air at 800$^\circ$C for 1 min. in the annealing-quenching mode. The results of X-ray phase analysis showed the formation of nanocrystalline solid solutions with a structure of hexagonal yttrium orthoferrite. The average crystallite size increases from 4 to 10 nm with the increasing bismuth content in the solid solution. The influence of Y$^{3+}$ substitution for Bi$^{3+}$ in yttrium orthoferrite on the photocatalytic activity of Y$_{1-x}$Bi$_x$FeO$_3$ nanopowders during the Fenton-like degradation of methyl violet under the visible light irradiation has been studied. The maximum reaction rate constant of 0.0197 min $^{-1}$ was shown by the YFeO$_3$ nanopowder, which has the smallest crystallite size of $\sim$4 nm.