C — Journal of Carbon Research

Sodium-ion batteries are generally considered a promising alternative to lithium-ion batteries due to the abundance and low cost of sodium. However, their main limitation is the lack of an appropriate anode, since the usual graphite electrode used in lithium batteries is incompatible with the larger ionic radius of sodium. In this work, the theoretical behavior of pillared graphene as a possible anode is analyzed via computational simulations based on Density Functional Theory (DFT) using the FIREBALL program. The structural relaxation results reveal that staggered pillars are more stable than the aligned alternative. The adsorption energy of sodium is shown to be significantly higher than for graphite, with a maximum value of $-2.23$ eV, leading to an important energetic benefit. The diffusion analysis shows high mobility for sodium, with migration barriers comparable to those of lithium ions both in the flat regions of the structure and close to the nanotubes. The values are comparable to those of the standard graphite used in current batteries. Finally, the charge analysis confirms significant electronic transfer from both sodium and lithium to the lattice. These data indicate that pillared graphene can be a good candidate for the optimization of charge dynamics in sodium-ion batteries.

This review examines the adsorption of trihalomethanes (THMs) by activated carbon by treating surface hydration and internal pore structure as a continuous and interconnected sequence of phenomena. At pore entrances, an initial hydration layer is first established, and the superposition of hydration retained by surface acidic functional groups on this water distribution may influence the accessibility of THM molecules to pore walls. Within micropores, particularly in the primary adsorption region corresponding to pore widths of 0.6–0.9 nm (6–9 Å), dispersion interactions dominate. In this region, the interfacial environment is affected by stepwise changes in the state of water, proceeding from isolated molecules to critical density and subsequent clustering. In addition, the connectivity of pores from access pores to the primary adsorption region may affect molecular mobility during penetration into the internal pore network and plays a crucial role in determining reachability under flowing water conditions. These phenomena do not act independently. Rather, five factors—(i) initial hydration at pore entrances, (ii) hydration environments retained around surface acidic functional groups, (iii) stepwise changes in water structure within the primary adsorption region, (iv) pore connectivity from access pores to the primary adsorption region, and (v) the characteristics of the primary adsorption region governing equilibrium capacity—interact at different spatial locations to collectively shape THM adsorption behavior. When an appropriate balance among these factors is achieved, both the accessibility and reachability of THMs to activated carbon surfaces are effectively expressed under practical operating conditions. This integrated understanding may contribute to improved drinking water safety by supporting the development of activated carbons with enhanced THM removal performance through the integrated control of pore architecture, surface chemistry, and hydration environments.

This study investigates the deposition of graphene oxide (GO) coatings on open-cell polyurethane foams through a soak-and-squeeze process for detergent removal. GO dispersions between 0.25 and 4 g/L were rheologically characterised to relate apparent viscosity to coating deposition. A first rationalisation of the squeeze-coating process was proposed by estimating the characteristic shear rates during squeezing, obtaining values of 12.2 s⁻¹ and 50.4 s⁻¹ for 20 and 60 PPI foams, respectively. Multiple deposition cycles were performed, achieving GO loads up to 12.7 wt% for both types of foam. The adsorption behaviour of GO powder toward a commercial detergent solution containing linear alkylbenzene sulphonate (LAS) was investigated at 25, 40 and 60 °C. UV-Vis spectroscopy was used to monitor concentration changes, while conductivity analyses investigated the temperature-dependent aggregation behaviour of the detergent system. The adsorption kinetics were well described by the Elovich model, suggesting adsorption on heterogeneous GO surfaces. Filtration tests using GO-coated foams showed a decrease in conductivity during flow-through experiments, whereas UV-Vis measurements indicated limited LAS removal under dynamic conditions, likely due to insufficient contact time between the detergent and the coated surface. Static contact tests performed for 1 h at 25 °C showed a reproducible detergent concentration decrease of approximately 16–18%. This value was further increased up to 65% under optimised conditions by modifying the GO-to-detergent ratio and foam configuration. The results demonstrate that the soak-and-squeeze approach is a simple and effective method for producing reproducible GO coatings on open-cell foams, while indicating that sufficient contact time is required to promote detergent removal.