Structural, compositional and textural properties of monoclinic α-Bi2O3 nanocrystals

Perfect alpha-Bi2O3 nanocrystals were successfully synthesized via green synthesis method. X-ray diffraction studies clearly revealed a single phase alpha-Bi2O3 nanocrystal without any secondary phase. The strong XPS peaks observed at 160 and 165 eV were assigned to Bi4f(5/2) and Bi4f(7/2) and clearly revealed Bi3+ valence states of bismuth ions. Photoluminescence spectra revealed the perfect alpha-Bi2O3 crystal nature without having inter band transitions between defects, impurity and different valence states of bismuth ions. Out of thirty expected modes, the symmetry assignments of Raman bands correlated to B-g(4), A(g)(5), B-g(5), B-g(6), A(g)(7), A(g)(8),A(g)(9),A(g)(10) , A(g)(12), and A(g)(14) modes revealed perfect alpha-Bi2O3 nanocrystals. Transmission electron microscopy studies combined with a selected area electron diffraction pattern recorded on alpha-Bi2O3 nanocrystals show monoclinic structure preferential orientation with sizes approximately 200 nm in diameters and 500 nm in length. (C) 2015 Elsevier B.V. All rights reserved.