Copper-based coordination polymer as a fast and efficient dye adsorbent from aqueous solutions

Green synthesis of a copper-based coordination polymer (Cu-CP) is reported utilizing a simple precipitation method. The prepared coordination polymer was characterized and used as a potent adsorbent for the elimination of organic dyes from aqueous solutions. The results of zeta potential analysis showed that the surface charge of the Cu-CP was −33.6 mV. In spite of negative surface charge and moderate specific surface area (99 m2·g−1), the prepared Cu-CP was a good adsorbent for removal of cationic e.g., malachite green (MG) and methylene blue (MB) as well as an anionic dye e.g., Congo red (CR). This efficiency could be attributed to π-π interaction and hydrogen bonding between adsorbent and adsorbate as the major forces leading to uptake of the dyes. However, MG with high removal efficiency (85.44%) at 2 min was chosen as a targeted dye for further consideration. Then, the effect of various parameters for adsorption of the MG e.g., adsorbent amount, pH, and initial concentration of dye were optimized. The adsorption isotherm and kinetic model for MG adsorption were also investigated. Finally, the adsorbent was reused after recycling which indicated high MG removal efficiency in successive tests.