Temperature-controlled assembly and morphology conversion of CoMoO4 center dot 3/4H(2)O nano-superstructured grating materials

Abstract

The regular and homogeneous single-crystal CoMoO4 center dot 3/4H(2)O nanorods, with the diameters ca. 100-300 nm and lengths ca. 8-15 mu m, have been successfully prepared by a simple and facile precipitation method. Their morphology conversion from broom-like to cage-like structure has been firstly reported through controlling the reaction temperature. The broom-like microbunches were obtained at 50 A degrees C while at 80 A degrees C, dispersive nanorods can be prepared. As the temperature reached 90 A degrees C, the morphology of the products converted to cage-like microspheres. SEM results show that the reaction temperature has a critical role in both the formation of the products and their morphologies. The UV-visible diffuse reflectance absorbance spectra of the products display two intense, broad absorbance bands cover almost the whole ultraviolet and visible region except for a narrow region around 450 nm, which is in the region for purple light. Based on the experimental results, a possible formation mechanism was also proposed. The synthesis strategy is simple, facile, mild, and has a good reproducibility. The as-prepared products may have potential applications in optics, catalysis, and grating materials.