Hydrogen-Rich Pyrolysis from Ni-Fe Heterometallic Schiff Base Centrosymmetric Cluster Facilitates NiFe Alloy for Efficient OER Electrocatalysts.

Binary metal nickel-iron alloys have been proven to have great potential in oxygen evolution reaction (OER) electrocatalysis, but there are still certain challenges in how to construct more efficient nickel-iron alloy electrocatalysts and maximize their own advantages. In this work, a heterometallic nickel-iron cluster (L = C ₆₄ H ₆₆ Fe ₄ N ₈ Ni ₂ O ₁₉ ) of Schiff base (LH ₃  = 2-amino-1,3-propanediol salicylaldehyde) is designed as a precursor to explore its behavior in the pyrolysis process under inert atmosphere. The combination of TG-MS, morphology, and X-ray characterization techniques shows that the Schiff base ligands in the heterometallic clusters produces a strong reductive atmosphere during pyrolysis, which enable the two 3d metals Ni and Fe to form NiFe alloys. Moreover, Fe ₂ O ₃ /Fe _0.64 Ni _0.36 @Cs carbon nanomaterials are formed, in which Fe ₂ O ₃ /Fe _0.64 Ni _0.36 is the potential active material for OER. It is also found that the centrosymmetric structure of the heterometallic Schiff base precursor is potentially related to the formation of the Fe ₂ O ₃ /Fe _0.64 Ni _0.36 alloy@carbon structures. The Fe ₂ O ₃ /Fe _0.64 Ni _0.36 @C-800 provides 274 mV overpotential in 1 m KOH solution at 10 mA cm ^-2 in OER. This work provides an effective basis for further research on Schiff base bimetallic doping-derived carbon nanomaterials as excellent OER electrocatalysts.
(© 2023 Wiley-VCH GmbH.)