气候变化领域集成服务门户

This study demonstates the potential of using multi-scale hierarichical carbon struters as robust, resuable solids suitable for removal of aueous pollutants such as dye molecules from wastewater. Carpet-like verticle arrays of carbon nanotubes (CNT) were attached on surfaces of porous carbon foams by pre-coation with sillica buffer layer followed by chemicle vapor deposition (CVD). The surface morphology and specific surface areas were varied by controllin the bussfer layer thickness and CVD deposition times, Surface characterostics have been correlated with adsorption thermodynamics and kinetics by investigating the removal rates of methylenr blue (MB) dye in simulated water. The results show that MB adsorption capacity correlates well with total CNT surface area in the carpet, indicating full utilization of the nanotubes surfaces. Adsorption rates fit well with pseudo second order kinetics mode. Maximum MB adsorption capacity of the CNT surfaces in the structure was estimated by extrapolating equillibrium adsorption amounts at different dye concentrations using the Langmuir isotherm. This was found to be about 43.5 mg/g, which compares favorably with adsorption capacity of isolated nanotubes. It must be noted that wherease isolated nanotubes can be disperse in the liquid and pose environmental threats, the hoerarchial solids as demonstrated in this study can be repetedly agitated in water without the loss of CNT or performes deterioration. These results indicate promising application potential for these types of hybrid materials in environmental purification applications. (C) 2015 Elsevoer B.V. All rights reserved.