SYNTHESIS AND EVALUATION OF RHODAMINE B ADSORPTION CAPACITY OF ALUMINUM TEREPHTHALATE METAL-ORGANIC FRAMEWORK MATERIAL

Abstract

In this paper, aluminum terephthalate metal-organic framework material, also known as MIL-53(Al), was synthesized with solvothermal method and employed as an adsorbent for the removal of rhodamine B from aqueous solution. The influence of as-synthesized MIL-53(Al) treated temperature to remove unreacted terephthalic acid molecules was investigated. The material was characterized by using X-ray diffraction, thermogravimetry analysis, Fourier-transform infrared spectroscopy, scanning electron microscopy, and nitrogen adsorption-desorption isotherms. The results show that as-synthesized MIL-53(Al) comprises the shape of rice grains with a length of about 0.3 mm and exhibits a large specific surface area (1028.3 m²/g). Calcination to remove remaining terephthalic acid molecules in the framework increases the crystallinity, but significantly reduces the specific surface area of the material. The metal-organic framework structure still persists in a treated temperature of 450 °C. The adsorption capacity of MIL-53(Al) to remove rhodamine B from aqueous solution was also evaluated via Freundlich and Langmuir isotherm models. The Freundlich model showed better fit to the adsorption data than the Langmuir model. The maximum adsorption capacity determined by the Langmuir model is 17.04 mg/g.