Oxygen evolution on NixFe3−xO4 electrodes

Effect of partial substitution of Cr on electrocatalytic properties of CoFe2O4CoFe2O4 towards O2O2-evolution in alkaline medium☆

“…For instance, at 100 mA cm −2 in 1 M KOH at 25 • C, Fe 3 O 4 , MnFe 2 O 4 , NiFe 2 O 4 and CoFe 2 O 4 recently obtained by a hydroxide precipitation method at controlled pH 11, produced the oxygen overpotentials 524, 338, 379 and 395 mV, respectively. These values of overpotentials are much lower than those obtained for similar anodes prepared by ceramic methods [9,10], but are comparable to those recently reported for Co 3 O 4 [14][15][16] and NiCo 2 O 4 [17][18][19]. Further, the overpotential data indicate that the effect of a d-electron deficient transition metal (i.e.…”

“…Fe 3 O 4 and its substituted products with the spinel structure of the type, AB 2 O 4 , where A and B are transition metals, possess relatively high overpotential [1] compared to cobaltites [2][3][4][5][6][7][8], for the oxygen evolution reaction (OER) in alkaline solution, and are scantly investigated for their use as oxygen anodes [2,9,10]. However, recent studies have shown [11][12][13] that the oxygen overpotential on ferrospinels can be reduced considerably by using low temperature preparation methods and substituting suitable metal ions for Fe in the Fe 3 O 4 -matrix partially.…”

Aerogel Architectures Boost Oxygen‐Evolution Performance of NiFe2Ox Spinels to Activity Levels Commensurate with Nickel‐Rich Oxides

“…Nickel–iron oxides (Ni a Fe b O x ), layered double hydroxides, and oxyhydroxides (Ni a Fe b OOH), including Ni 1− x Fe x metallic films that form oxyhydroxy species in situ, are reported to be among the most active transition‐metal OER catalysts in alkaline electrolytes; the performance of Ni‐rich compositions approaches that of RuO 2 or IrO 2 . For a series of transition‐metal oxides, mixed Ni‐rich iron oxides deliver high initial activity at 10 mA cm −2 at relatively low overpotentials: 336 mV for Ni 0.9 Fe 0.1 O x and 340 to 350 mV for 1:1 Ni/Fe in Ni 0.5 Fe 0.5 O x .…”

“…Nickel-iron oxides( Ni a Fe b Ox), layered double hydroxides, and oxyhydroxides (Ni a Fe b OOH), including Ni 1Àx Fe x metallic films that form oxyhydroxys pecies in situ, are reported to be among the most activet ransition-metal OER catalysts in alkaline electrolytes;t he performance of Ni-rich compositions ap-proachest hat of RuO 2 or IrO 2 . [10,16,25,[26][27][28][29][30][31][32][33][34][35][36] For as eries of transition-metal oxides, mixed Ni-rich iron oxidesd eliver high initial activity at 10 mA cm À2 at relatively low overpotentials:3 36 mV for Ni 0.9 Fe 0.1 Ox [16] and 340 [11] to 350 mV [10] for 1:1N i/Fe in Ni 0.5 Fe 0.5 Ox.A nother studyw ith aN i-richi ron oxide found an in situ conversion to aN iFe 2 O 4 /NiOx composite with NiFe 2 O 4 spineli dentified as the active phase. [37] We now reportc ompetitive activity for OER (an overpotential of 356 mV at ac urrent density of 10 mA cm À2 )w ith an ominally single-phase, Fe-rich NiFe 2 Ox spinel, once this composition is expressed as ah ighsurface-area pore-solid architecture.…”

Low Temperature Synthesis and Characterization of NixFe3-xO4 (0≤x≤1.5) Electrodes for Oxygen Evolution Reaction in Alkaline Medium

“…Initially, these oxides were prepared by high temperature thermal decomposition [23] methods which requires prolong heating and materials obtained have low specific surface area as well as low electrocatalytic activity. During recent decades, various preparation methods like freeze-drying [24], citrate precursor techniques [25], co-precipitation [26], sol-gel [27], hydrothermal [28] etc. have been developed to obatain the spinel oxides.…”