On the Iron Oxidation State in the Iron-Substituted γ Nickel Oxyhydroxides

Electrochemical study of the promoting effect of Fe on oxygen evolution at thin ‘NiFe–Bi’ films and the inhibiting effect of Al in borate electrolyte

“…38 FeIJIII), CoIJIII) and AlIJIII) reportedly stabilize α-NiIJOH) 2 and the α/γ couple, possibly because their greater charge increases anion bonding between sheets and hinders transformation to β-NiIJOH) 2 . [39][40][41][42][43] A positive shift in the NiIJOH) 2 /NiOOH peaks and greater reversibility have been reported with Fe incorporation, and the NiIJOH) 2 /NiOOH peaks also depend on the phase with α/γ reported to be more reversible and β(II)/β(III) to occur at more positive potentials (although some studies could have involved Fe inclusion in the electrolyte). 17,20,24,36 Fe is thus pictured to substitute for Ni sites in Ni-Bi during co-deposition resulting in Fe-α-NiIJOH) 2 .…”

“…To investigate further the effect of Fe inclusion on Ni-Bi, we compared the effects of adding to the electrolyte Fe 3+ versus Al 3+ at the same concentration, as Al 3+ has a similar size and the same change as Fe 3+ and is similarly known to substitute for Ni 2+ sites and to stabilize View Article Online α-NiIJOH) 2 /γ-NiOOH. [39][40][41][42][43] Fig. 4 shows CVs (at 10 mV s −1 ) of Ni-Bi) 1mC before and then after adding 0.16 mM Al 3+ (source 1, 99.999% Al) or 0.16 mM Fe 3+ to 1 M KBi, and then after acquiring 10 CVs at 100 mV s −1repeated six times.…”

In-situ structure and catalytic mechanism of NiFe and CoFe layered double hydroxides during oxygen evolution

“…In spite of previous reports on the ex-situ crystal structure of the as-synthesized precursors of MFe LDH catalysts [23][24][25][26][27][28] and insitu local structure based on X-ray absorption spectroscopy (XAS) measurements 3,4,12,[29][30][31][32] , little is known about the long-range crystal structures of the catalytically active phase under OER conditions. As a result, most proposals regarding the in-situ crystal structures of NiFe and CoFe LDHs under OER conditions are indirectly inferred from the crystal structures of the host Ni and Co oxyhydroxides, respectively.…”

``In-situ'' spectro-electrochemical studies of radionuclide-contaminated surface films on metals

“…As the peak at ~3.10 Å is relatively weak we find that this interaction can also be represented as a Cr-Cr correlation at 3.44 (5) There has been a number of studies designed to understand the local atomic and electronic structure of iron and other metal ions incorporated into α-Ni(OH) 2 [23][24][25][26][27][28][29]. For brevity, we omit discussion of previous works here.…”