Abstract In this paper, we report a simple two-step approach to prepare porous octahedron- and rod-shaped ZnO architectures. The morphology of porous ZnO particles can be conveniently tuned by controlling morphologies of the ZnC 2O 4·2H 2O precursor. SEM and TEM characterization results indicate that these porous ZnO architectures are built up by numerous ZnO primary nanoparticles with random attachment. Based on thermogravimetry analysis, we believe that the release of water vapor, CO and CO 2 leads to the formation of high-density pores in shape-controlled particles during the calcination process. Further experimental results indicate that as-prepared porous ZnO particles exhibit good photocatalytic activity due to large surface area.