Preparation of a Bimetallic NiFe‐MOF on Nickel Foam as a Highly Efficient Electrocatalyst for Oxygen Evolution Reaction

Abstract

A series of bimetallic metal‐organic frameworks (MOFs) were prepared on three‐dimensional nickel foam (NF) using a one‐pot synthesis, marked as NiFe‐MOF/NF. The structure of the as‐prepared NiFe‐MOF/NF was characterized by X‐ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscope (TEM), X‐ray photoelectron spectroscopy (XPS), FT‐IR and Raman. Compared with the monometallic Ni‐MOF material, the incorporation of Fe greatly changes the inherent properties of Ni‐MOF. Electrochemical measurement results show the optimized NiFe‐MOF/NF [Ni : Fe=3 : 7 (molar ratio)] has better electrocatalytic performance and the current densities of 50 mA cm−2 and 100 mA cm−2 have low overpotentials of 225 mV and 251 mV, respectively, for the oxygen evolution reaction in alkaline solution. In particular, the inverse curve of linear sweep voltammetry shows an ultralow overpotential of only 160 mV at current density of 10 mA cm−2. NiFe‐MOF/NF also has excellent stability and can run continuously for at least 50 h. NiFe‐MOF/NF has remarkable OER performance, which is mainly due to the high conductivity, the large specific surface area and the synergistic effects of Fe and Ni in MOFs. The work presents a general strategy for the synthesis of electrocatalytic materials for effective and scalable electrocatalytic water oxidation.

Formation of NiFe-MOF nanosheets on Fe foam to achieve advanced electrocatalytic oxygen evolution

“…3a and b, NiFe-MOF/FF-0.5 reaches a current density of 50 mA cm −2 with a minimum overpotential of 216 mV, which is significantly lower than those of Ni-MOF-FF (344 mV), Fe-MOF/FF (336 mV), and blank FF (398 mV). Importantly, compared with many advanced MOF-based catalysts reported recently, this low overpotential is quite or even lower, such as MIL-53(FeNi)/NF ( η 50 mA cm −2 = 233 mV), 24 NiFe-MOF/NF ( η 50 mA cm −2 = 225 mV), 23 NiCo-C/NF ( η 10 mA cm −2 = 260 mV), 28 FCN-MOF/NF ( η 10 mA cm −2 = 196 mV), 20 and other bimetallic MOFs (Table S2†). With the increase of current density, NiFe-MOF/FF-0.5 has more obvious advantages.…”

“…Therefore, direct growth of MOF nanosheets on the conductive substrate to construct a self-supporting electrode is an effective method, which has many advantages such as improved conductivity and abundant catalytic sites for excellent OER performance. [17][18][19] Compared with mono-metal MOFs, bimetal MOFs have been proved to show advanced OER electrocatalytic performance, because of the strong coupling effects between the two metals, [20][21][22] such as NiFe-MOFs, [23][24][25][26][27] NiCo-MOFs, 28,29 and FeCo-MOFs. 30,31 Among various bi-metal-based electrocatalysts, the Ni-Fe systems show the most extensive application prospects.…”

An efficient photocatalysis-self-Fenton system based on Fe(ii)-MOF/g-C3N4for direct hydroxylation of benzene to phenol

“…Major C1 was usually attributed to standard carbon, while C2 and C4 peaks at 285.9 and 288.7 eV were attributed to carboxyl groups (O–CO) in organic ligands. 25 The smaller peak (287.0 eV) C3 in the photocatalytic composite Fe( ii )-MOF/g-C 3 N 4 was assigned to sp 2 hybrid carbon atoms (N–CN) in g-C 3 N 4 . 26 The N 1s XPS spectra of the two samples were deconvoluted into three peaks located at 398.5 and 400.4, corresponding to bicoordinated nitrogen (N 2C ), and tricoordinated nitrogen (N 3C ) in the heptazine framework, respectively (Fig.…”

Binder-Free Defective Bimetallic Metal-Organic Framework Nanostructures with Lattice Distortion as Hybrid Supercapacitor Electrodes

“…Figure S5 shows the FTIR spectra of the other electrodes, demonstrating their similar features. The intensity ratio of the characteristic peaks of the antisymmetric −COO– stretching to the para-substituted C–H stretching decreased with increasing BA content, indicating that BA was introduced into the MOF . Molecular vibrational characterization is mainly studied by Raman spectroscopy …”

“…The intensity ratio of the characteristic peaks of the antisymmetric −COO− stretching to the para-substituted C−H stretching decreased with increasing BA content, indicating that BA was introduced into the MOF. 33 Molecular vibrational characterization is mainly studied by Raman spectroscopy. 34 Figure 4c displays the Raman spectra of 10% Ni/Co-MOF/NF.…”