A facile morphological specific precipitation method by volumetric control of the precursors has been demonstrated to achieve tetrapod-like and dodecahedron-like Ag3PO4 microparticles, which show superior visible-light responsive of photocatalytic activity when comparing to TiO2 (P25). This study also reveals that the tetrapod-like Ag3PO4 microparticles exhibit significantly higher photocatalytic activity (95.6% degradation within 20 min, k: 0.1937 min−1) than the dodecahedrons (78.9% degradation within 30 min, k: 0.0593 min−1) for the degradation of rhodamine B (RhB, 10 ppm) under low-power white light-emitting diode irradiation (300 mW cm−2), which may be attributed to the high reactivity of {110} facets. Moreover, holes and superoxide radicals were the main reactive species involved in RhB degradation.