Metal organic framework-derived nitrogen-doped nanoporous carbon as an efficient adsorbent for methyl orange removal from aqueous solution

Abstract

Abstract In this work, nitrogen-doped nanoporous carbon (N-NC-800) was successfully synthesized through a facile strategy involving the direct carbonization of amino-functionalized aluminum terephthalate metal organic framework (CAU-1-NH2) under nitrogen atmosphere. N-NC-800 was characterized by X-ray powder diffraction, Raman spectroscopy, N2 sorption isotherm, scanning electron microscopy and high-resolution transmission electron microscopy. The adsorption performance of N-NC-800 was assessed in the removal of Methyl Orange (MO), a model toxic anionic dye, from aqueous solution. Experiments have been performed to study the effects of several parameters including solution pH, time, initial MO concentration and adsorbent dosage on the sorption efficiency. N-NC-800 exhibited excellent adsorption ability for MO and also showed good reusability. Under the optimal experimental conditions, MO removal percentage can reach up to 98.5% and the adsorbent can be reused for at least five times in succession without remarkable loss of adsorption efficiency. Moreover, the adsorption process fitted very well with a pseudo-second-order model and the adsorption equilibrium data were well described by the Langmuir isotherm. In light of its facile synthesis, superior adsorption capacity and excellent reusability, MOF-derived nitrogen-doped nanoporous carbon can be deemed as a potentially promising adsorbent for the highly-efficient removal of anionic dye contaminants from polluted industrial effluents.