Preparation and Adsorption Properties of Lithium Chloride Intercalation Carbon Nitride

In recent years, the pollution of organic wastewater to the environment has attracted extensive attention. The adsorption method is simple and has been used for the adsorption of organic dyes in wastewater. In this study, lithium chloride (LiCl) was intercalated on graphite like carbon nitride (g-C3N4), a series of Li intercalated g-C3N4 adsorbents (Li/GCN-x) were synthesized. And use X-ray diffraction (XRD), field emission scanning electron microscopy (SEM), N-2 adsorption-desorption and other methods to comprehensively test and characterize the phase structure, morphology, and surface area of the prepared samples. At the same time, the influence of the amount of LiCl added on the adsorption of methylene blue (MB) on the intercalation material at room temperature was investigated. The optimal Li content in the intercalation g-C3N4 was determined. The research results show that compared with pure g-C3N4, the prepared Li/GCN-5 can form fibers with uniform diameters between the layers, XRD results show that the addition of LiCl makes the lattice of g-C3N4 expand and the layer spacing expand, indicating the successful intercalation of LiCl. The pH and the binding time between the adsorbent and MB were studied. The new functional groups of the adsorbent can form hydrogen bonds with MB molecules and interact through pi-pi bonds. When only 50 mg of the adsorbent is added, the maximum adsorption capacity can reach 704 mg.g(-1) in 5 min. In addition, adsorption kinetics simulations have been carried out. The results show that the intercalation adsorbent can adsorb MB. The model conforms to the quasi-second-order kinetic equation. The Weber-Morris model was further used to explore the adsorption control process. The results showed that the adsorption of MB was caused by the combined action of surface diffusion and intrapore diffusion, in which surface diffusion was dominant, and the newly added functional groups could form hydrogen bonds with MB molecules, and the interaction enhances the adsorption capacity through pi-pi bonds. The as-prepared materials in this study are stable, uniform and have large specific surface area, which can simply and quickly realize the adsorption of MB. It provides a simple, low-cost, and efficient method for the adsorption and removal of organic pollutants, which overcomes the shortcomings of slow kinetics of commonly used adsorbents.