Hydrogen sorption on microporous carbon/sulfur nanocomposite systems

Encapsulating sulfur in single-walled carbon nanotubes (S@SWCNTs) produces a composite material hitherto unexplored for hydrogen storage. Interactions between sulfur and carbon nanotubes modify the electronic properties of the composite, thus offering methods for improving hydrogen sorption in carbon nanotubes. Here we demonstrate that S@SWCNT composites can provide 35% greater gravimetric excess adsorbed hydrogen per unit specific surface area, and improved hydrogen uptake at lower pressures (<2 MPa), indicating higher enthalpies of adsorption. Through semi-empirical modelling of high-pressure gas sorption isotherms, it was determined that S@SWCNTs can provide 74% higher volumetric hydrogen density compared to an undoped equivalent at 2 MPa and 77 K.

Automated summary

Encapsulating sulfur in single-walled carbon nanotubes enhances the hydrogen adsorption capacity by modifying the electronic properties. Experimental results showed that the S@SWCNT composites can adsorb more hydrogen per unit specific surface area and exhibit improved hydrogen uptake at lower pressures.