Journal ArticleDOI
The role of the Auger parameter in XPS studies of nickel metal, halides and oxides
TLDR
Auger parameter analysis indicates that the bonding in NiO appears to have stronger contributions from initial state charge transfer from the oxygen ligands than that in the hydroxide and oxyhydroxide consistent with the considerable differences in the Ni-O bond lengths in these compounds with some relaxation of this state occurring during final state phenomena.Abstract:
The critical role of the Auger parameter in providing insight into both initial state and final state factors affecting measured XPS binding energies is illustrated by analysis of Ni 2p3/2 and L3M45M45 peaks as well as the Auger parameters of nickel alloys, halides, oxide, hydroxide and oxy-hydroxide. Analyses of the metal and alloys are consistent with other works, showing that final state relaxation shifts, ΔR, are determined predominantly by changes in the d electron population and are insensitive to inter-atomic charge transfer. The nickel halide Auger parameters are dominated by initial state effects, Δe, with increasing positive charge on the core nickel ion induced by increasing electronegativity of the ligands. This effect is much greater than the final state shifts; however, the degree of covalency is reflected in the Wagner plot where the more polarizable iodide and bromide have greater ΔR. The initial state shift for NiO is much smaller than those of Ni(OH)2 or NiOOH and the effective oxidation state is much less than that inferred from the average electronegativity of the ligand(s). Auger parameter analysis indicates that the bonding in NiO appears to have stronger contributions from initial state charge transfer from the oxygen ligands than that in the hydroxide and oxyhydroxide consistent with the considerable differences in the Ni–O bond lengths in these compounds with some relaxation of this state occurring during final state phenomena. The Auger parameter of NiOOH is, however, shifted positively, like the iodide, indicating greater polarizability of the ligands and covalency in this bonding. There is support for more direct use of relative bond lengths in interpreting differences between related compounds rather than more general electronegativity or similar parameters.read more
Citations
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Journal ArticleDOI
Amorphous nickel hydroxide nanospheres with ultrahigh capacitance and energy density as electrochemical pseudocapacitor materials
H. B. Li,Minghao Yu,Fenghua Wang,P. Liu,Yongju Liang,J. Xiao,C. X. Wang,Yexiang Tong,G. W. Yang +8 more
TL;DR: The integrated electrochemical performance of the amorphous nickel hydroxide is commensurate with crystalline materials in supercapacitors, and these findings promote the application ofAmorphous nanostructures as advanced electrochemical pseudocapacitor materials.
Journal ArticleDOI
Advanced analysis of copper X-ray photoelectron spectra
TL;DR: In this article, the authors extend and extend previously published X-ray photoelectron spectroscopy curve-fitting and data analysis procedures for a wide range of copper containing species.
Journal ArticleDOI
Amorphous Ni(OH)2 @ three-dimensional Ni core–shell nanostructures for high capacitance pseudocapacitors and asymmetric supercapacitors
TL;DR: In this article, a complex hydroxide/metal Ni(OH)2@Ni core-shell electrode was developed for a highperformance and flexible pseudocapacitor.
Journal ArticleDOI
Ambient-Pressure XPS Study of a Ni-Fe Electrocatalyst for the Oxygen Evolution Reaction
Harri Ali-Löytty,Harri Ali-Löytty,Mary W. Louie,Mary W. Louie,Meenesh R. Singh,Meenesh R. Singh,Lin Li,Hernan Sanchez Casalongue,Hirohito Ogasawara,Ethan J. Crumlin,Zhi Liu,Alexis T. Bell,Alexis T. Bell,Anders Nilsson,Daniel Friebel +14 more
TL;DR: In this paper, a thin film of Ni-Fe oxyhydroxide electrodeposited on Au as the working electrode at different applied potentials in 0.1 M KOH as the electrolyte.
Journal ArticleDOI
Impact of nanoparticle size and lattice oxygen on water oxidation on NiFeOxHy
Claudie Roy,Bela Sebok,Søren Bertelsen Scott,Elisabetta Maria Fiordaliso,Jakob Ejler Sørensen,Anders Bodin,Daniel Bøndergaard Trimarco,Christian Danvad Damsgaard,Peter Christian Kjærgaard Vesborg,Ole Hansen,Ifan E. L. Stephens,Ifan E. L. Stephens,Jakob Kibsgaard,Ib Chorkendorff +13 more
TL;DR: In this article, the authors used a model system of mass-selected NiFe nanoparticles and isotope labelling experiments to show that oxygen evolution in 1'M KOH does not proceed via lattice exchange.
References
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Resolving surface chemical states in XPS analysis of first row transition metals, oxides and hydroxides: Sc, Ti, V, Cu and Zn
TL;DR: Biesinger et al. as mentioned in this paper proposed a more consistent and effective approach to curve fitting based on a combination of standard spectra from quality reference samples, a survey of appropriate literature databases and/or a compilation of literature references and specific literature references where fitting procedures are available.
Book
Practical surface analysis: By auger and x-ray photoelectron spectroscopy
David Briggs,M. P. Seah +1 more
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Investigation of multiplet splitting of Fe 2p XPS spectra and bonding in iron compounds
TL;DR: In this paper, the authors investigated the usefulness of calculated multiplet peaks to fit high-resolution iron 2p3/2 spectra from high-spin compounds. And they found that the multiplets were found to fit most spectra well, particularly when contributions attributed to surface peaks and shake-up satellites were included.
Journal ArticleDOI
Band gaps and electronic structure of transition-metal compounds
TL;DR: A new theory is presented for describing band gaps and electronic structures of transition-metal compounds and both the metallic sulfides and insulating oxides and halides occur in a quite natural manner.