CO2 Capture and Gas Storage Capacities Enhancement of HKUST-1 by Hybridization with Functionalized Graphene-like Materials

Biocompatible Hybrid Graphenic Thin Coatings on Flexible Substrates through Matrix-Assisted Pulsed Laser Evaporation (MAPLE)

This work reports the production of biocompatible thin layers for biomedical applications based on a graphene-like material (GL), a graphene-related material (GRM) obtained from carbon black. GL was combined in a hybrid fashion with polydopamine (pDA), a mussel-inspired water-resistant wet adhesive bonding obtained by the oxidative polymerization of dopamine (DA), and polyvinyl pyrrolidinone (PVP), a nontoxic synthetic polymer with intrinsic adhesion properties, to obtain a tighter adhesion of the thin layer to the substrate (silicone slices). Matrix-assisted pulsed laser evaporation (MAPLE) was used to coat PDMS slices with thin films of GL-pDA and GL-PVP directly from their frozen suspensions in water. The results indicate that the relevant chemical-physical characteristics of both thin films (evidenced by FTIR and AFM) were maintained after MAPLE deposition and that the films exhibit uniformity also at the nanometric level. After deposition, the GL-pDA and GL-PVP films underwent a biological survey toward murine fibroblasts (NIH3T3), human keratinocytes (HaCAT), and human cervical adenocarcinoma epithelial-like (HeLa) cells to assess the feasibility of this approach. Results indicate that both the GL-pDA and GL-PVP films did not perturb the biological parameters evaluated, including cytoskeleton alterations. Both hybrid films enhanced the effects of GL on cellular vitality across all cell lines. Specifically, the GL-pDA film exhibited a more stable effect over time (up to 72 h), whereas the GL-PVP film behaved similarly to the GL film in NIH3T3 and HeLa cell lines after long-term exposure. These promising results make the GL-pDA and GL-PVP films potential candidates for the manufacture of coated flexible devices for biomedical applications.

Metal-organic frameworks as photocatalysts in energetic and environmental applications

Metal-organic frameworks (MOFs) are an exciting new class of porous materials with great potential for photocatalytic applications in the environmental and energy sectors. MOFs provide significant advantages over more traditional materials when used as photocatalysts due to their high surface area, adaptable topologies, and functional ability. In this article, we summarize current developments in the use of MOFs as photocatalysts for a variety of applications, such as CO2 reduction, water splitting, pollutant degradation, and hydrogen production. We discuss the fundamental properties of MOFs that make them ideal for photocatalytic applications, as well as strategies for improving their performance. The opportunities and challenges presented by this rapidly expanding field are also highlighted.

Carbon Dioxide Capture by Adsorption in a Model Hydroxy-Modified Graphene Pore

Concerns regarding the environmental impact of increasing levels of anthropogenic carbon dioxide have led to a variety of studies examining solid surfaces for their ability to trap this greenhouse gas (GHG). Atmospheric or post-combustion carbon capture requires an efficient separation of carbon dioxide and nitrogen gas. We used the molecular mechanics MM3 parameter set (previously shown to provide good estimates of molecule-surface binding energies) to calculate theoretical surface binding energies for carbon dioxide ∆E(CO₂) and nitrogen ∆E(N₂). For efficient separation, differentiation of these two gas-surface adsorption energies is required. Examined structures based on graphene, carbon slit width pore, and carbon nanotube gave ∆E(CO₂) to ∆E(N₂) ratios of 1.7, 1.8, and 1.9, respectively. To enhance the CO₂ adsorption, we developed a model graphene surface pore lined with four hydroxy groups whose orientation allowed them to form hydrogen bonds with the oxygens in CO₂. Both the single-layer and double-layer versions of this pore gave significant enhancement in the ability to trap CO₂ preferentially to N₂. The two-layer version of this pore gave ∆E(CO₂) = 73 and ∆E(N₂) = 6.8 kJ/mol. The one- and two-layer versions of this novel pore averaged a ∆E(CO₂) to ∆E(N₂) ratio of 12.