b-Ni(OH)2/NiFe2O4 heterostructure composite derived from layered double hydroxides precursor for ethanol oxidation electrocatalysis

We reported facile fabrication of a novel I3-Ni(OH)2/NiFe2O4 heterostructure composite by KOH alkaline etching three-component NiFeAl-layered double hydroxides (NiFeAl-LDHs) precursor for ethanol oxidation electrocatalysis. Detailed investigation of evolution prog-ress from NiFeAl-LDHs precursor to I3-Ni(OH)2/NiFe2O4 demonstrated that growth of such composite structure underwent partial dealumination and spontaneous lattice rear-rangement of NiFeAl-LDHs to form a-Ni(OH)2/NiFeAl-LDHs compound, followed by deep dealumination and topological transformation to produce I3-Ni(OH)2/NiFe2O4. Compared to NiFeAl-LDHs precursor, I3-Ni(OH)2/NiFe2O4 heterostructure prepared in 15 M KOH alkaline had enhanced activity (approximately 10 times) for ethanol electrocatalysis, smaller elec-tron transfer resistance of 1.33 U, and increased long-term stability. In situ diffuse reflec-tance infrared Fourier transform spectroscopy (DRIFTS) and in situ Raman spectroscopy were further performed to explore reaction mechanism and transformation process of I3-Ni(OH)2/NiFe2O4 in ethanol electrocatalysis, which verified that the process of electron donating and electron receiving between NiFe2O4 and p-Ni(OH)2 realized more electron transfer and greatly improved the fuel utilization.& COPY; 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.