Effect of interlayer anions on [NiFe]-LDH nanosheet water oxidation activity

We synthesized nickel–iron layered double hydroxide ([NiFe]-LDH) nanosheets with different interlayer anions to probe their role in water oxidation catalysis. In alkaline electrolyte in ambient air, carbonate rapidly replaced other interlayer anions and catalytic activity was highest. Electrocatalytic water oxidation in virtually carbonate-free alkaline electrolyte revealed that activity was a function of anion basicity. Our [NiFe]-LDH nanosheets, prepared by pulsed laser ablation in liquids, were regenerated in carbonate-containing aqueous KOH. Anion binding motifs were assessed by X-ray photoelectron spectroscopy in combination with density functional theory calculations, suggesting that nitrite species bound to edge-site Fe in the precatalyst correlated with higher water oxidation activity

In situ UPS study of the formation of FeSi films from cis-Fe(SiCl 3)2(CO)4

Organometallics17265825-5829ORGN

Effect of interlayer anions on [NiFe]-LDH nanosheet water oxidation activity

Powering the planet with sustainable, carbon-neutral fuels affects every aspect of human life. Sunlight-driven water splitting is an attractive soln. to provide environmentally benign hydrogen fuel. Global scalability demands that all photoelectrode and catalyst materials consist of earth- abundant elements. The water oxidn. half reaction requires four coupled electron and proton transfer steps, for which robust and efficient electrocatalysts are needed. We have shown previously that [NiFe] - layered double hydroxide (LDH) nanosheets are highly active water oxidn. catalysts [Hunter, Blakemore, Deimund, Gray, Winkler, Mueller, J. Am. Chem. Soc. 2014, 136, 13118]. They were synthesized by pulsed laser ablation in liqs. (PLAL), a medium-throughput method that yields small, monodisperse, surfactant- free, size and compn. controlled nanomaterials [Blakemore, Gray, Winkler, Mueller, A. M. ACS Catal. 2013, 3, 2497]. Our [NiFe]-LDH nanosheets are among the best earthabundant water oxidn. catalysts, reaching 10 mA cm^(-2) at only 280 mV overpotential on a flat electrode in 1 M aq. KOH. We have now investigated the effect of interlayer anions on water oxidn. activity. Our [NiFe]-LDH materials consisted of sheets of edge- shared nickel oxide octahedra, with 22 % of ferric iron substituting at nickel sites. The excess pos. charges of Fe^(3+) substituting for Ni^(2+) were balanced by interlayer anions; water was also present in the interlayer galleries. The small size (<20 nm) of our nanosheets made by PLAL allowed for complete exchange of interlayer anions simply by soaking in aq. solns. We synthesized twelve materials with different interlayer anions, either by anion exchange or directly by PLAL, and assessed their water oxidn. activity in strong aq. base. Const.- current electrolysis data showed that the basicity of interlayer anions matters for water oxidn. catalysis. The catalysts were most active and self- healing in self-buffered carbonate-contg. alk. electrolyte

"Inverted'' porphyrins: a distorted adsorption geometry of free-base porphyrins on Cu(111)

COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPBased on density functional theory calculations combined with experimental results, we report and discuss an extremely distorted, "inverted" adsorption geometry of free-base tetraphenylporphyrin on Cu(111). The current findings yield new insights into a well-studied system, shedding light on the peculiar molecule-substrate interaction and the resulting intramolecular conformation.535882078210COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPPROBRAL 435/15Sem informaçãoFunding by the Deutsche Forschungsgemeinschaft (DFG) within the Cluster of Excellence EXC 315 "Engineering of Advanced Materials'' (www.eam.uni-erlangen.de) and the Research Unit FOR 1878 (funCOS) is gratefully acknowledged. A. S. acknowledges funding from CAPES (PROBRAL 435/15) and FAPESP from Brazil. H. M. and M. L. are grateful for funding through DAAD PROBRAL projects 57143062 and 5735014

On surface synthesis of heptacene and its interaction with a metal surface

Heptacene was generated by surface-assisted didecarbonylation of an α-diketone precursor on a Ag(111) surface.</p

Observation of the Inverse Trans Influence (ITI) in a Uranium(V) Imide Coordination Complex: An Experimental Study and Theoretical Evaluation

An inverse trans influence has been observed in a high-valent U­(V) imide complex, [((^AdArO)₃N)­U­(NMes)]. A thorough theoretical evaluation has been employed in order to corroborate the ITI in this unusual complex. Computations on the target complex, [((^AdArO)₃N)­U­(NMes)], and the model complexes [((^MeArO)₃N)­U­(NMes)] and [(NMe₃)­(OMe₂)­(OMe)₃U­(NPh)] are discussed along with synthetic details and supporting spectroscopic data. Additionally, the syntheses and full characterization data of the related U­(V) trimethylsilylimide complex [((^AdArO)₃N)­U­(NTMS)] and U­(IV) azide complex [((^AdArO)₃N)­U­(N₃)] are also presented for comparison

Uranium(III) Complexes with Bulky Aryloxide Ligands Featuring Metal–Arene Interactions and Their Reactivity Toward Nitrous Oxide

We report the synthesis and use of an easy-to-prepare, bulky, and robust aryloxide ligand starting from inexpensive precursor materials. Based on this aryloxide ligand, two reactive, coordinatively unsaturated U­(III) complexes were prepared that are masked by a metal–arene interaction via <i>δ</i>-backbonding. Depending on solvent and uranium starting material, both a tetrahydrofuran (THF)-bound and Lewis-base-free U­(III) precursor can easily be prepared on the multigram scale. The reaction of these trivalent uranium species with nitrous oxide, N₂O, was studied and an X-ray diffraction (XRD) study on single crystals of the product revealed the formation of a five-coordinate U­(V) oxo complex with two different molecular geometries, namely, square pyramidal and trigonal bipyramidal

Uranium(III) Complexes with Bulky Aryloxide Ligands Featuring Metal–Arene Interactions and Their Reactivity Toward Nitrous Oxide

We report the synthesis and use of an easy-to-prepare, bulky, and robust aryloxide ligand starting from inexpensive precursor materials. Based on this aryloxide ligand, two reactive, coordinatively unsaturated U­(III) complexes were prepared that are masked by a metal–arene interaction via <i>δ</i>-backbonding. Depending on solvent and uranium starting material, both a tetrahydrofuran (THF)-bound and Lewis-base-free U­(III) precursor can easily be prepared on the multigram scale. The reaction of these trivalent uranium species with nitrous oxide, N₂O, was studied and an X-ray diffraction (XRD) study on single crystals of the product revealed the formation of a five-coordinate U­(V) oxo complex with two different molecular geometries, namely, square pyramidal and trigonal bipyramidal