Effect of purification treatment on adsorption characteristics of carbon nanotubes

Enhanced electrochemical hydrogen storage by catalytic Fe-doped multi-walled carbon nanotubes synthesized by thermal chemical vapor deposition

“…The oxidized MWCNTs exhibited a higher specific surface area and pore volume as compared to the raw and purified MWCNT samples. The same results have been reported by Chen et al [33] for the MWCNTs grown by La-Ni catalyst.…”

“…5 depicts N 2 adsorption isotherms of the raw, oxidized and purified MWCNTs. Adsorption isotherms of the oxidized and purified MWCNTs exhibited an increase in N 2 adsorption below P/P o = 0.05, confirming the existence of the microporous structures in the oxidized and purified MWCNTs [33,34]. The isotherms also indicated adsorption hysteresis behavior of the oxidized and purified MWCNTs in the P/P o > 0.3, due to capillary condensation in the mesopores (Fig.…”

Properties that Influence the Specific Surface Areas of Carbon Nanotubes and Nanofibers

“…Increases in BET surface area have been seen after removal of amorphous carbon through thermal treatment and after acid treatment to remove metal impurities associated with CNTs (Eswaramoorthy et al ., 1999; Li et al ., 2003; Chen et al ., 2007). The increase is partially due to an increase in the surface accessible for nitrogen adsorption after removal of impurities.…”

“…Results for two Timesnano SWCNTs (1–2-nm OD; 5–30-μm length) having purities of >90% (Sample 2) and >60% (Sample 8) show an increase in surface area for the lower purity product, from 367 to 392 m 2 g −1 , which is not expected based on most literature reports (Eswaramoorthy et al ., 1999; Li et al ., 2003; Chen et al ., 2007). The SSAs for both materials are lower than those reported by the supplier, >380 m 2 g −1 for high-purity SWCNTs and >407 m 2 g −1 for low-purity SWCNTs, but the relative results are consistent.…”

Carbon nanostructures with different dimensionality – From synthesis to applications

“…Microwave-assisted purification of CNTs in acid solutions have also appeared in recent years [158,159,160,161]. It exploits the fact that concentrated acid was found to rapidly absorb microwaves, allowing a quick dissolving of metal particles without the damaging of tubes.…”