Synthesis of CuBDC metal-organic framework supported zinc oxide via ball-milling technique for enhanced adsorption of Orange-II

For the first time, copper-based metal-organic framework (CuBDC) supported ZnO composite was successfully prepared by the ball-milling method for effective adsorption of anionic azo orange-II (OII) dye. After comparing the OII adsorption performances of ZnO and composites, with two different CuBDC support ratios, focused on the investigation of 1:1 CuBDC@ZnO. The crystal structures, physicochemical properties, and surface morphologies of the adsorbents were characterized by XRD, FTIR, SEM-EDX, and BET analyses. The adsorption process fitted the Langmuir isotherm model (R2=0.98) and the monolayer adsorption capacity of 1:1 CuBDC@ZnO composite was found to be 132.12 mg g-1. The adsorption process was well described by the pseudo-second-order model, which indicates the adsorption process of 1:1 CuBDC@ZnO composite on OII is chemisorption. Moreover, 1:1 CuBDC@ZnO composite can be an alternative as an effective and innovative adsorbent for the removal of toxic OII dye contaminant.