In this study, a series of Ag3PO4 photocatalysts with different contents of rhombic dodecahedral particles were prepared in one pot by a facile, novel hydrothermal method using ethylene glycol (EG), which served as both a morphology modifier and reducing agent. The effects of EG content on the morphologies of Ag3PO4 photocatalysts were discussed. The photocatalytic activity of the Ag3PO4 photocatalysts was evaluated by the degradation of methylene blue trihydrate under visible-light irradiation. With the use of 0.8% EG in the reaction solvent, the sample exhibited excellent photocatalytic activity, attributed to the high amount of rhombic dodecahedral Ag3PO4 particles with a high exposure of the {110} facets and high surface energy. The surface energy of the {110} facets was 1.31 J/m(2), greater than that of the {100} facet (1.12 J/m(2)). However, with 1% EG in the reaction solvent, although the Ag3PO4 photocatalysts were composed of a majority of rhombic dodecahedral Ag3PO4 particles, tiny Ag particles formed from Ag+ under the action of EG attached on the surface of the sample decreased the absorption of visible light, resulting in low photocatalytic activity. (C) 2016 Elsevier B.V. All rights reserved.