Synthesis of Cu-BTC Metal-Organic Framework by Ultrasonic Wave-Assisted Ball Milling with Enhanced Congo Red Removal Property

Cu-BTC (BTC=1,3,5-benzenetricarboxylate) metal-organic framework (MOF) with truncated octahedral morphology was synthesized by ultrasonic wave-assisted ball milling at room temperature and atmospheric pressure. It was characterized by X-ray powder diffraction (XRD), thermo-gravimetric analysis (TGA), nitrogen adsorption and scanning electron microscopy (SEM). The parameters such as synthetic method, reaction time and raw material molar ratio (H3BTC: Cu2+) were studied to tune the growth of Cu-BTC crystals. Adsorption of Congo red (CR) on Cu-BTC was studied in respect of adsorption kinetics, isotherm and thermodynamics. Pseudo-second-order kinetics and Langmuir adsorption isotherm model were matched well with the adsorption process. The maximum adsorption capacity (Q(m)) was 884.96 mg/g, attributed to the interfacial effect in (100) facets. Thermodynamic parameters confirmed that the adsorption was a spontaneous and endothermic process, and entropy effect was the driving force for adsorption process.