High surface area montmorillonite-carbon composites and derived carbons

The intercalation of sugar in smectite clays and the resulting clay-carbon composites after thermal treatment in Ar are described. Sugar activation by H2SO4 treatment affords novel clay-carbon composites in which the layer structure of clay is preserved. Combined XRD and TEM measurements strongly suggest that carbonization at 600 degreesC leads to graphenes distributed over the clay surfaces, forming a nanometric carbonaceous film. Thermal analysis and XRD results show enhanced thermal stability of the clay-carbon composites with the mineral preserving its layered structure even at 900 degreesC. Acid demineralization of the clay substrate yields novel carbonaceous materials of high surface areas. The templating role of clay substrate in the growth of the carbonaceous layer is revealed by HRTEM micrographs, which show limited packing of graphenes accompanied by improved surface areas. The present clay-carbon composites are low-temperature-synthesized absorbents without the need of high-temperature activation.