A novel mesoporous carbon nanospheres-based adsorbent material with desirable performances for dyes removal

Abstract

Nowadays, the reduction of dye contaminants in the aquatic environment has attracted widespread research attention. In this work, a novel mesoporous carbon nanospheres (MCNs)-based material as an adsorbent for dye removal was achieved by the carbonization of a composite of sucrose and aluminum sulfate without involving any hazardous activators. The as-obtained MCNs were analyzed by TG, XRD, FESEM, TEM, Raman, BET and XPS, meanwhile the batch experiments of Congo red (CR), Malachite green (MG) and Methylene blue (MB) on the MCNs were conducted to explore the impact of adsorption conditions on the adsorption process, respectively. Results show that the MCNs exhibit a uniform spherical morphology as well as partially graphitic structure with a large surface area of 449.25 m2/g, a relatively narrow pore size distribution and a high pore volume of 0.57 cm3 g−1. The unique porous structure of the MCNs endows it with high adsorption capabilities for dyes, including CR (1726.60 mg g−1), MG (980.55 mg g−1) and MB (708.82 mg g−1), suggesting its high adsorption capability for both anionic and cationic dyes. Meanwhile, the adsorption process is demonstrated to follow the Langmuir model and pseudo-second-order kinetic model, respectively, and the main adsorption mechanisms may involve pore filling, π-π conjugation, electrostatic attraction and hydrogen bonding. Furthermore, the as-synthesized adsorbent displays good recyclability performance for remaining relatively high sorption performance even after five regeneration cycles.