3D flower-like zinc pyrovanadate (Zn-3(OH)(2)V2O7 center dot 2H(2)O) microstructure has been successfully prepared via a simple chemical precipitation process at 70 degrees C for 10 h, and no surfactant or any template was employed during the entire synthetic process. Moreover, smaller-scale zinc pyrovanadate 3D flower-like microspheres were also prepared with different amounts of polyvinylpyrrolidone (PVP) as surfactant. On basis of time dependent experiments, a possible formation mechanism of zinc pyrovanadate 3D flower-like microspheres was proposed. The results exhibited that particle size of the as-synthesized samples significantly has influence on their photocatalytic activity for degradation of methylene blue (MB), and the sample with the smallest size (under the highest PVP concentration) showed the highest photocatalytic activity. (C) 2014 Elsevier B.V. All rights reserved.