Chitosan-based nitrogen-rich mesoporous carbon by magnesium oxide template method and its adsorption property to chlorogenic acid

A rapid preparation method for high performance nitrogen-rich mesoporous carbon materials based on chitosan (CS) was explored, and its application potential in chlorogenic acid (CGA) enrichment. The mesoporous carbon (MgO-CSMC) was prepared using CS as carbon and nitrogen sources, as well as MgO nanoparticles as template, for rapid and high-capacity enrichment of CGA. Structural and morphological characterization revealed that nano-sized MgO as a template facilitated the formation of abundant mesopores, endowing MgO-CSMC with an exceptionally high specific surface area (1948 m²/g) and significant nitrogen (3.6%) and oxygen (7.3%) content. The adsorption capacity of MgO-CSMC for CGA reached up to 652 mg/g, and rapid adsorption was achieved. The adsorption mechanism showed that the adsorption of the MgO-CSMC for CGA was mainly physical adsorption, conforming to the Langmuir isothermal adsorption model and pseudo-second-order kinetic model. In addition, the adsorption thermodynamic analysis indicated that the adsorption process of the MgO-CSMC for CGA was exothermic, reversible and spontaneous. This work provides a novel route for the preparation of high-performance nitrogen-rich mesoporous carbon materials and an efficient and sustainable solution for the separation and purification of bioactive ingredients.