Size-controlled synthesis and photocatalytic properties of YMnO3 nanoparticles

Nanocrystalline YMnO3 samples with average particle size ranging from 85 to 45 nm have been synthesized through a polyacrylamide gel route. The optical energy bandgap of the samples has been measured by optical absorption, and is shown to increase with decreasing particle size from 1.23 eV for 85 nm to 1.31 eV for 45 nm. The photocatalytic experiments reveal that the as-prepared YMnO3 nanoparticles exhibit a pronounced photocatalytic activity for the decomposition of methyl red under ultraviolet and visible light irradiation, and the photocatalytic efficiency increases with decreasing the particle size. (C) 2010 Elsevier B.V. All rights reserved.