Three-dimensional nanoflowers were successfully synthesized by using a simple self-assembly reaction of sandwich polyoxometalate, [P2W18Ce3(H2O)2O71]12− (P2W18Ce3) and diethylenetriamine. The results showed that the size and morphology of the nanoflowers are controlled by diethylenetriamine concentration and reaction cultivation time. This reaction is mainly proceeded by hydrogen bonds formation and electrostatic interaction between polyoxometalate and alkylamine. The results showed that by calcining the catalytic efficiency of inorganic–organic nanohybrids improved. Further investigations showed that, the issue quality, the morphology of inorganic–organic nanohybrids and the structure of the polyoxometalate have changed due to calcination. The catalysts were characterized by Fourier transforms infrared, powder X-ray diffraction, scanning electron microscopy, N2 adsorption–desorption isotherms and thermogravimetric analyses, and their catalytic efficiency in the .decomposition reaction of cationic and anionic dyes and oxidation of sulfide was investigated
