An exsolution constructed FeNi/NiFe₂O₄ composite: preferential breaking of octahedral metal–oxygen bonds in a spinel oxide

Abstract

Exsolution as an ingenious strategy to in situ construct metal or alloy decorated oxide has been extended from perovskite to spinel for its promising energy related catalysis application. To identify...

Sodium Tartrate-Assisted Synthesis of High-Purity NiFe2O4 Nano-Microrods Supported by Porous Ketjenblack Carbon for Efficient Alkaline Oxygen Evolution

“…More profoundly, the introduction of cheap and commercially available KB during the synthesis of NiFe 2 O 4 /KB and CoFe 2 O 4 /KB produced catalysts with much higher OER activities compared with the corresponding ferrite counterparts (NiFe 2 O 4 and CoFe 2 O 4 ). The η 10 value of 258 mV (vs RHE) measured for NiFe 2 O 4 /KB is one of the smallest values yet reported for ferrite-based electrocatalysts during OER (Table S1), − ,,,,,,− outperforming NiFe 2 O 4 /carbon cloth (340 mV vs RHE), NiFe 2 O 4 /FeNi 3 foam (262 mV vs RHE), NiFe 2 O 4 /Ti 3 C 2 (266 mV vs RHE), NiFe 2 O 4 /Ni@C (330 mV vs RHE), NiFe 2 O 4 -hollow nanoparticles/CNTs (260 mV vs RHE), and NiFe 2 O 4 /rGO (302 mV vs RHE) . Few ferrite-based composite catalysts have been reported with η 10 values lower than NiFe 2 O 4 /KB, though most have complicated compositions and cumbersome preparation routes, such as phosphided NiFe/NiFe 2 O 4 embedded into porous N-doped carbon nanospheres (P-FeNi/FeNiO/CNS, 220 mV vs RHE) or 3D porous CoFe 2 O 4 /C nanorod arrays supported on Ni foam@polyaniline (Ni foam@NC-CoFe 2 O 4 /C, 240 mV vs RHE) …”

Recent advances in exsolved perovskite oxide construction: exsolution theory, modulation, challenges, and prospects

“…The exsolution of Ru results in the rearrangement of oxygen vacancies around the Ru atoms in the parent lattice, leading to the conversion of Sm 2 Ru 0.2 Ce 1.8 O 7 to Ru(0)/Sm 2 Ce 1.8 O 7− δ . Guo et al 109 used inverse spinel NiFe 2 O 4 (NFO) as a prototype and exsolved NiFe alloy under 5% H 2 in Ar at 500 °C. The embedded structure ensures strong interfacial interaction between the exsolved FeNi alloy and the parent spinel, which enhanced the charge transfer ability.…”

Synthesis and advantages of spinel-type composites

“…12f-k. 151 For the past few years, the self-transformation or rational design of amorphous materials have attracted wide attention for achieving high activity. [152][153][154] Our group developed an ultrasonicassisted reduction method to construct amorphous NiFe(OH) x on the basis of NiFe 2 O 4 .…”