Construction of a polyoxoniobate compound in strong alkaline medium and adsorption behavior for cationic dyes

Polyoxoniobate {[Na-6(H2O)(14)][Nb6O19]}center dot 2H(3)O center dot H2O (compound 1) was successfully synthesized in strong alkaline medium by hydrothermal method. The spectra and structural feature of the compound 1 was characterized by IR, UV-Vis DRS, thermogravimetry and PXRD. The framework of the compound 1 consist of polyoxoniobate anionic cluster ([Nb6O19](8)) and sodium water cluster Na-6(H2O)(14). Adjacent [Nb6O19](8) were connected by the sodium water cluster with coordinated bond to assemble 3D structure. Based on the adsorption experiment, seven kinds of dyes with different electrical properties and sizes were selected to investigate their adsorption behavior. The adsorption mechanism of compound 1 with anionic framework is an electrostatic process and therefore has a better adsorption effect on cationic dyes.

Automated summary

Compound 1, polyoxoniobate {[Na-6(H2O)(14)][Nb6O19]}center dot 2H(3)O center dot H2O, was successfully synthesized in strong alkaline medium using the hydrothermal method. Its structure consists of polyoxoniobate anionic cluster and sodium water cluster, which allows for strong adsorption of cationic dyes.