Visible-light-responsive alpha-beta phase heterojunction on Bi2O3 nanowire photocatalysts were prepared via a facile in situ hydrothermal process in assistance with the post-heat treatment route. The as-prepared samples were characterized by X-ray diffraction (XRD), electron microscope (EM), Brunauer-Emmett-Teller analysis (BET), X-ray photoelectron spectroscopy (XPS), and UV-vis diffuse reflectance absorption spectra (UV-vis). XRD patterns revealed that the alpha-beta phase heterojunction over Bi2O3 composites with the monoclinic alpha-Bi2O3 and the tetragonal beta-Bi2O3 structure were obtained and the relative ratios between alpha-Bi2O3 and beta-Bi2O3 can readily be tailored by the control of the reaction temperature. Within the hydrothermal temperature range, the morphology of as-prepared samples transformed progressively from two-dimensional beta-Bi2O3 sheets to the alpha-/beta-Bi2O3 nanowires junction. The exceptional photocatalytic performance of alpha-/beta-Bi2O3 heterojunction for the degradation of cationic rhodamine B and anionic methyl orange under visible-light irradiation is superior over that of beta-Bi2O3 sheets, which is ascribed to the efficient charge separation and transfer across the alpha-beta phase junction. The phase-junction approach will open new avenues for the development of efficient photocatalysts for environmental remediation and energy conversion. (c) 2013 The Authors. Published by Elsevier B.V. All rights reserved.