Preparation of Nanostructured TaN Electrodes by Alkaline Hydrothermal Treatment Followed by NH Annealing and Their Improved Water Oxidation Performance.

Solar water splitting is a clean and sustainable process for green hydrogen production. It can reduce the fossil fuel consumption. Tantalum nitride (TaN) is one of the limited candidates of semiconductors, which absorb a broad range of visible light and are thermodynamically able to split water without external bias potential.

A new preparation of a bifunctional crystalline heterogeneous copper electrocatalyst by electrodeposition using a Robson-type macrocyclic dinuclear copper complex for efficient hydrogen and oxygen evolution from water.

The development of low-cost, stable bifunctional electrocatalysts, which operate in the same electrolyte with a low overpotential for water splitting, including the oxygen evolution reaction and the hydrogen evolution reaction, remains an attractive prospect and a great challenge. In this study, a water soluble Robson-type macrocyclic dicopper(ii) complex has been used for the first time as a catalyst precursor for the generation of a copper-based bifunctional heterogeneous catalyst film, which can be used for both HER and OER at a near neutral pH. In sodium borate buffer at pH 9.

The secondary coordination sphere and axial ligand effects on oxygen reduction reaction by iron porphyrins: a DFT computational study.

Oxygen reduction reaction (ORR) catalyzed by a bio-inspired iron porphyrin bearing a hanging carboxylic acid group over the porphyrin ring, and a tethered axial imidazole ligand was studied by DFT calculations. BP86 free energy calculations of the redox potentials and pK a's of reaction components involved in the proton coupled electron transfer (PCET) reactions of the ferric-hydroxo and -superoxo complexes were performed based on Born-Haber thermodynamic cycle in conjunction with a continuum solvation model. The comparison was made with iron porphyrins that lack either in the hanging acid group or axial ligand, suggesting that H-bond interaction between the carboxylic acid and iron-bound hydroxo, aquo, superoxo, and peroxo ligands (de)stabilizes the Fe-O bonding, resulting in the increase in the reduction potential of the ferric complexes.

The secondary coordination sphere controlled reactivity of a ferric-superoxo heme: unexpected conversion to a ferric hydroperoxo intermediate by reaction with a high-spin ferrous heme.

A bio-inspired heme complex involving both a proton donor and an axial imidazole ligand reduces the activation energy for the formation of a ferric hydroperoxo intermediate. A high-spin ferrous heme is shown to be capable of reducing its superoxy species to generate a ferric hydroperoxo intermediate for the first time.

A cryo-generated ferrous-superoxo porphyrin: EPR, resonance Raman and DFT studies.

The resonance Raman analysis of cryo-generated ferrous-superoxy heme has been performed for the first time, and its structure and the reaction mechanism are rationalized by DFT calculations. The presence of another electronic tautomer of ferrous-superoxy heme is predicted computationally.