Carbon Tube Clusters with Nanometer Walls Thickness, Micrometer Diameter from Biomass, and Its Adsorption Property as Bioadsorbent

Carbon tube clusters with nanometer wall thickness and micrometer diameter were prepared by carbonizing the pappi of Sonchus oleraceus L. Such tube clusters possessed micropores, mesopores, and large specific surface area (911 m2 g–1). The adsorption properties of the carbon tube clusters were further evaluated by choosing metal ions, dye, lubricating oil, and waste oil as the targets, respectively. The maximum adsorption capacities of the materials for lubricating oil and waste oil were 103.76 and 91.70 g g–1, respectively, which benefit from abundant pore structure, large specific surface area, and hydrophobic property. Such tube clusters also demonstrated excellent adsorption property for metal ions such as Ag+, which exhibited extremely high selectivity (the highest selectivity coefficient to Cd2+ was 1021.88) and fast adsorption rate (the adsorption amount reached 91% of equilibrium adsorption capacity within 10 min). Because of low cost and simple preparation and being a renewable resource, the prepared carbon tube clusters possess great potential as an efficient adsorbent for cleaning marine oil spills and selectively recycling silver ions.