This paper report a facile route of synthesizing Ag3PO4 crystal with smooth surface, and La-doped Ag3PO4 crystal with porous surface by accurately controlling the kinetic parameters during chemical precipitation process. As a result of surface modification induced by La doping, the La-doped Ag3PO4 crystal shows a higher photocatalytic activity than Ag3PO4 crystal in O-2 evolution from water splitting. The improved photocatalytic activity of La-doped Ag3PO4 is attributed to the synergistic effects of porous surface structure, abundant surface defects and increased surface area. The result also shows that La doping concentration has a remarkable effect on the photocatalytic activity of Ag3PO4. (C) 2014 Elsevier Inc. All rights reserved.