Synthesis of FeNiCo Ternary Hydroxides through Green Grinding Method with Metal‐Organic Frameworks as Precursors for Oxygen Evolution Reaction

Abstract

Metal‐organic framework (MOF)‐derived materials have been widely applied to diversified fields until now due to their flexible processibility. Different kinds of suitable materials can be synthesized by varying MOF templates/precursors and synthesis methods. An appropriate method can skillfully fabricate the materials with excellent performance while meeting the environmentally friendly concept. In this work, a green and flexible grinding method was introduced to synthesize MOF‐derived FeNiCo trimetallic materials without solvent‐assistance, in which Co‐ZIF‐L was selected as a sacrificial precursor and Fe3+ and Ni2+ as etchants and dopants. Surprisingly, the as‐prepared FeNiCo ternary hydroxides supported on Ni foam (G‐FeNi‐Co‐ZIF‐L/NF) showed superior electrocatalytic performance for the oxygen evolution reaction (OER) with a low overpotential of 248 mV at 10 mA cm−2. This work provides a prospective approach to synthesize various MOF‐derived multi‐metallic materials, which also opens the door for syntheses of OER electrocatalysts.

Enhanced Electrocatalytic Oxygen Evolution by In Situ Growth of Tetrametallic Metal–Organic Framework Electrocatalyst FeCoNiMn-MOF on Nickel Foam

“…Furthermore, to delve into the causation of the exceptional OER activity, XPS analysis was conducted to examine the electronic state of the electrode surface. As illustrated in Figure , consistent with XRD results, the XPS survey spectra revealed a significant alteration in the composition and valence state of elements following the electrolysis process. − As shown in the Fe 2p spectrum, Fe 2+ has deconvoluted peaks located at 713.5 and 724.7 eV; the newly emerged signal at 710.9 eV could be attributed to Fe 3+ . According to electrochemical performance test results, the Fe-based composite electrode usually presents a better OER activity due to the additional induced structural vacancies of Fe 3+ , which could accelerate electron transfer .…”

Prominent development of Ni-based oxygen-evolving electrocatalysts for water splitting

“…142 Nowadays, advanced studies on trimetallic and further multimetal materials for OER catalysis have been highly promising. Therefore, a variety of trimetallic metal materials such as FeCoNi alloys, 145 FeCoNiO x , 144,146,147 NiFeWO x , 33,[148][149][150][151][152] FeCoNi phosphides, 153 Cr-doped FeCoNiO x , 154 NiFeMoO x , 155 NiFeBaO x , 156 NiFeMg oxyhydroxide, 157 FeNiCr hydroxide 158 and alloy, 159 MnFeNi hydroxide 157 and alloy, 160 NiCoV boride, 161 and NiFeMoB alloy 162 have been developed as OER catalysts. Moreover, HECs are a type of catalyst materials composed of four or more metals and have a high degree of configurational entropy.…”

“…14b). 147 G-FeNi-Co-ZIF-L was loaded on an NF substrate, showing an OER performance with η 10 = 248 mV and Tafel slope of 49.5 mV dec −1 in 1.0 M KOH. The authors presumed that the performance may be mainly improved by the increase in the number of active sites on the additional Fe and Ni centers and the synergistic effect among the multi-metal components; however, direct evidence for the synergistic effect was not provided.…”

“…Overall, the incorporation of non-precious metals to the improve OER performances can be a more prospective from the viewpoint of element strategy. Many existential investigations demonstrated the incorporation of Fe and Co in Ni-based catalysts to develop bimetallic 13,21,104,106,202,203 and trimetallic 81,[144][145][146][147]154,[181][182][183][184][185] catalysts and HECs. 163,[173][174][175][176][177][178][179][180]204 Interestingly, the third metals of W, 33,[148][149][150][151][152] Mo, 155,162,186 Ba (ref.…”