Selective Adsorption Performance of H6P2Mo15W3O62-based Cu3(BTC)2 Composite in Treatment of Simulated Cationic Dye Wastewater

摘要

Removal of methylene blue(MB) from aqueous solution by a new polyoxometalate-based metal-organic framework composite(POM@MOF) was systematically explored in batch tests.The chemical structure and surface properties of the composite were characterized by means of FTIR,XRD,EDS,N2 adsorption-desorption isotherms and zeta potential measurements.The results showed that MB adsorption onto H6P2Mo15W3O62@Cu3(BTC)2 highly depended on initial solution pH,which was mainly related to the electrostatic attraction between negatively charged composite surface and positively charged MB molecules.Thus,the improved adsorption performance of H6P2Mo1sW3O62@Cu3(BTC)2 can be attributed to the modification of H6P2Mo1sW3O62 resulting in its higher electronegative charge than Cu3(BTC)2.The thermodynamic parameters indicated that the adsorption was spontaneous and exothermic process.The isotherm obtained fitted the Langmuir model and the maximum adsorption capacity of the composite at 30 ℃ was 77.22 mg/g.All the results illustrated that H6P2Mo1sW3O62@Cu3(BTC)2 composite can effectively and selectively remove cationic organic pollutants,represented by MB,implying the promising application of designing a novel adsorbent polyoxometalate-based metal-organic frameworks in treatment of dye wastewater.