Three cobalt(III) complexes of regioisomeric trans-A 2 B-corroles were designed and efficiently synthesized. The corroles were adsorbed on smooth glassy carbon (GC) and black pearls 2000 (BP2000), high-surface-area carbon. Albeit spatially separated from the cobalt reaction center, the position of COOH group has a profound influence on the oxygen reduction reaction electrocatalytic reactivity when on GC, whereas on BP2000, a significant increase in selectivity toward the 4-electron reduction was observed in an alkaline environment. This is attributed to the wetting properties of the hydrophobic pores of BP2000, which considerably lower the dielectric constant in the pore water environment, stabilize the charged OOH − intermediate, and favor the 4-electron reduction pathway with the cobalt-bis-pentafluorophenyl (phenyl-para-carboxylic acid), when compared to analogous corroles with the COOH group at the ortho-and meta-positions.

One of the bottlenecks toward the successful implementation of alternative energies is the lack of methods for sustainable generation of hydrogen fuel as an energy carrier. Given that water will be at the very least an important component of the hydrogen production feedstock, sustainable catalysts are needed for the electrochemical generation of hydrogen from water. Herein, we report on the electrochemical activation of a silver-based catalyst for the efficient hydrogen evolution reaction (HER) in acidic conditions at high current densities. After activation, the catalyst is chemically and electrochemically stable over days. The starting material, silver sulfide, is synthesized by a simple and scalable chemical vapor deposition process. Upon electrochemical activation, the pristine material is converted to mesoporous silver coated with a silver oxo-sulfide layer which is highly active toward HER. Detailed microscopy and spectroscopy demonstrate the formation of both hydroxyl and sulfoxide groups on the surface of the catalyst. Interestingly, the density functional theory calculations suggest that only in the presence of these hydroxyl groups will sulfur atoms exhibit high catalytic activity with a hydrogen binding energy of −0.35 eV.

We constructed a simple atomistic potential capable of accurately reproducing the energetics of the carbon vacancy arrangements in cubic Mo2C and Ti2C obtained from density functional theory (DFT) calculations.

When producing stable electrodes, polymeric binders are highly functional materials that are effective in dispersing lithium-based oxides such as Li4Ti5O12 (LTO) and carbon-based materials and establishing the conductivity of the multiphase composites. Nowadays, binders such as polyvinylidene fluoride (PVDF) are used, requiring dedicated recycling strategies due to their low biodegradability and use of toxic solvents to dissolve it. Better structuring of the carbon layers and a low amount of binder could reduce the number of inactive materials in the electrode. In this study, we use computational and experimental methods to explore the use of the poly amino acid poly-L-lysine (PLL) as a novel biodegradable binder that is placed directly between nanostructured LTO and reduced graphene oxide. Density functional theory (DFT) calculations allowed us to determine that the (111) surface is the most stable LTO surface exposed to lysine. We performed Kubo–Greenwood electrical conductivity (KGEC) calculations to determine the electrical conductivity values for the hybrid LTO–lysine–rGO system. We found that the presence of the lysine-based binder at the interface increased the conductivity of the interface by four-fold relative to LTO–rGO in a lysine monolayer configuration, while two-stack lysine molecules resulted in 0.3-fold (in the plane orientation) and 0.26-fold (out of plane orientation) increases. These outcomes suggest that monolayers of lysine would specifically favor the conductivity. Experimentally, the assembly of graphene oxide on poly-L-lysine-TiO2 with sputter-deposited titania as a smooth and hydrophilic model substrate was investigated using a layer-by-layer (LBL) approach to realize the required composite morphology. Characterization techniques such as X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), Kelvin probe force microscopy (KPFM), scanning electron microscopy (SEM) were used to characterize the formed layers. Our experimental results show that thin layers of rGO were assembled on the TiO2 using PLL. Furthermore, the PLL adsorbates decrease the work function difference between the rGO- and the non-rGO-coated surface and increased the specific discharge capacity of the LTO–rGO composite material. Further experimental studies are necessary to determine the influence of the PLL for aspects such as the solid electrolyte interface, dendrite formation, and crack formation.