One-step synthesis of highly porous carbon graphite/carbon nanotubes composite by in-situ growth of carbon nanotubes for the removal of humic acid and copper (II) from wastewater

Abstract Porous carbon graphite/carbon nanotubes composite was prepared in a one-step process. Carbon nanotubes (CNTs) were grown in-situ simultaneously with the formation of the porous carbon material. Two plastic pastes, with and without ferrocene as catalyst for CNTs growth were prepared by mixing at room temperature a thermosetting phenolic resin, a graphite powder and cellulose derivatives. Both pastes were shaped and carbonized at 800 °C under N2. The porosity of materials was correlated to the weight losses induced by the cellulose derivatives decomposition and phenolic resin carbonization. Both X-ray powder diffraction and Raman analysis showed that iron nanoparticles and FexC complexes were formed following the decomposition of ferrocene and apparently catalyzed the growth of CNTs. Moreover, SEM and TEM images demonstrated that CNTs were grown in different shapes and sizes. High porosities of 45.4% and 52.3% were achieved for carbon graphite and carbon graphite/CNT composite, respectively. The presence of the CNTs drastically changed the surface properties and the electrical conductivity of the material. When tested as adsorbents of humic acid and copper (II) ions from aqueous solutions, it turned out that CNTs presence enhanced the adsorption. Furthermore, oxidation of the carbon graphite/CNT composite enhanced significantly the adsorption but had no effect on the pure carbon graphite material.