Construction and topological studies of a three dimensional (3D) coordination polymer showing selective adsorption of aromatic hazardous dyes

Abstract

Here we report the synthesis of a 3D coordination polymer, [Cd4(CH3COO)4(μ-OH)4·C2H5OH]n (CP1) of cadmium acetate via solvothermal synthesis under high temperature and pressure conditions for 72 h. It was characterized by single crystal X-ray diffraction (SCXRD), FTIR, powder X-ray diffraction (PXRD) and thermogravimetric (TGA) techniques. Surface area and porosity were determined by BET analysis. Further, TEM results show structural variability and morphological information of CP1. The X-ray analysis confirms that the CP1 was crystallized in a monoclinic system with square pyramidal geometry resulting from the bidentate acetate ions and hydroxide ions. The topological studies suggest that the CP1 is having binodal nodes with kgd topological network. The CP1 was employed as dye adsorbent for both MB (methylene blue) and MO (methyl orange) dyes, which are considered as harmful organic pollutants. Moreover, CP1 has shown selective adsorption with good adsorption efficiency for MB dye at room temperature and high pH value. The adsorption mechanism was considered to be based on the electrostatic and H-bonding interactions. The adsorption kinetic model reveals that it follows pseudo second order kinetics. Interestingly, CP1 is displaying unique structural and topological features with better adsorption properties towards organic pollutants, hence it can be employed as an effective dye adsorbent for future applications.