Green and simple production of graphite intercalation compound used sodium bicarbonate as intercalation agent

In view of the technical difficulties in the preparation of graphite intercalation compound (GIC) such as complex processes, the need to use strong acid reagents, and the product containing corrosive elements. A novel, efficient and simple method used sodium bicarbonate as intercalation agent was developed, which combined with mechanical force and chemical method for the green production of GIC. The production parameters were optimized by the single factor experiments, the optimal conditions were the ball mill speed 500 r/min for 4 h (6 mm diameter of the stainless-steel beads as ball milling media), the decomposition temperature 200 ℃ for 4 h, and 1:1 mass ratio of flake graphite to sodium bicarbonate. SEM results revealed that the prepared product appears the lamellar separation, pores, and semi-open morphology characteristic of GIC. FT-IR results indicated that the preparation method does not change the carbon-based structure, and the sodium bicarbonate intercalant has entered the interlayer of graphite flakes to form GIC. XRD results further showed that the GIC products still maintained the structure of carbon atoms or molecules, and the sodium bicarbonate intercalation agent has entered the interlayer of the graphite, and increased the interlayer distance of the layered graphite. The expandability of GIC products was studied, and the results show that it was expandable, and the expandable volume of GIC products prepared under optimal conditions has reached 142 mL/g. The theoretical basis for large-scale production was provided by studied the mechanism of the preparation method and designed the flow chart. The method has the advantages of simple process, products free of impurities, no use of aggressive reagents, process stable, and does not pollute the environment, being favorable to mass production, and provided new preparation method and idea for two-dimensional nanomaterials with preparation technical difficulties.

The removal of pentavalent arsenic by graphite intercalation compound functionalized carbon foam from contaminated water

In the present investigation, Graphite intercalation compound (GIC) functionalized phenolic resin based carbon foam for removal of arsenic (As(V)) from contaminated water is developed by sacrificial template technique followed by carbonization at 1000 °C in N₂. The GICCF adsorbent is characterised by scanning electron microscope (SEM) for morphological study, X-ray diffraction (XRD) patterns explains the phase information and interlayer spacing of the adsorbent, whereas Fourier Transform Infrared Spectroscopy (FTIR) and X-ray Photoelectron Spectroscopy (XPS) gives the information about surface functionality and mechanism of adsorption of As(V) over the surface of adsorbent. The time data is fitted well in pseudo second order kinetics and follows multilinear nature of intra-particle diffusion model. The adsorption nature of adsorbent and adsorbate is explained by Langmuir isotherm better than Freundlich isotherm, Temkin isotherm, and D-R isotherm. The adsorption capacity of adsorbent is 62.5 μgg^-1, which is calculated by Langmuir isotherm. Arsenic removal by GICCF is taken place within two hrs up to acceptable limit. The proposed GICCF can be regenerated after treating with 0.1 M HNO₃ and 0.1 M HCl solution and it can be used for multiple times.

Disinfection of water by adsorption combined with electrochemical treatment

The disinfection performance of a unique process of adsorption combined with electrochemical treatment is evaluated. A flake graphite intercalation compound adsorbent was used, which is effective for the removal of organic contaminants and is amenable to anodic electrochemical regeneration. Adsorption of Escherichia coli on the graphite flake was followed by electrochemical treatment under a range of experimental conditions in a sequential batch reactor. The adsorption of E. coli cells was found to be a fast process and was capable of removing >99.98% of cells from solution after 5 min with a ca. 6.5-log10 reduction in E. coli concentration after 10 min. With electrochemical treatment the adsorbent could be reused, with no decrease in E. coli adsorption observed over five cycles. In the presence of chloride, >8.5-log10 reduction of E. coli concentration was achieved. Disinfection was found to be less effective in the absence of chloride. However, selection of appropriate operating conditions enabled effective disinfection in a chloride free system, reducing the potential for formation of disinfection by-products. The energy consumption required to achieve >8.5-log10 disinfection was 2-7 kWh m(-3).