Metal–Organic Framework-Derived Bimetallic NiFe Selenide Electrocatalysts with Multiple Phases for Efficient Oxygen Evolution Reaction

Abstract

The development of efficient and stable transition bimetallic chalcogenides to replace precious metal electrocatalysts for alkaline oxygen evolution reaction (OER) remains an ongoing challenge. Here, a bimetallic NiFe selenide catalyst synthesized by facile selenization of NiFe Prussian blue analogue (PBA) metal–organic framework (MOF) nanoparticle precursors is reported for efficient OER in alkaline solutions. Through two-step electrodeposition and post-thermal pyrolytic selenization, mixed NiFe selenide supported by carbon fiber paper (NiFe-Se/CFP) can be facilely prepared. A low overpotential of 281 mV is required by the NiFe-Se/CFP electrode to deliver a current density of 10 mA cm–2; additionally, an accelerated electron-transfer kinetics is obtained with a Tafel slope of 40.93 mV dec–1 in 1 M KOH solution. The electrocatalytic current density shows negligible loss during 20 h continuous electrolysis, suggesting good stability during long-term alkaline OER. Using the MOF precursor and establishing an in situ phase transformation endow mixed NiFe selenide with highly active surface catalytic sites and high electrical conductivity for efficient water oxidation.

Research Progress of Oxygen Evolution Reaction Catalysts for Electrochemical Water Splitting

“…Recently, Shi and co‐workers [125] achieved highly efficient OER in alkaline solution by combining bimetallic NiFe selenide catalysts with MOF nanoparticle precursors of NiFe Prussian blue analogue (PBA), as shown in Figure 18. The prepared NiFe−Se/CFP (carbon fiber paper) electrode showed high OER activity in 1.0 m KOH.…”

Carbon-Based Composites as Electrocatalysts for Oxygen Evolution Reaction in Alkaline Media

“…This method is most frequently applied for direct selenization of the metal precursor and is usually carried out in a tubular furnace where Se powder (but also S or Te) is placed in a crucible in the upstream side of the tube and the metal/carbon precursor downstream. The furnace is purged with an inert gas, usually argon, and kept between 350 and 500 °C (usually 450 °C) for 2–3 h. The precursor is frequently in the form of a Prussian blue analogue (PBA) [ 117 , 118 ] or a zeolitic imidazolate framework (ZIF) type metal–organic framework (MOF) compound where the metal is reduced before selenization [ 119 , 120 ].…”

“…Another bimetallic NiFe PBAs as MOF precursors were electrodeposited on carbon fiber paper (CFP) and were put inside a tube furnace with the Se powder in a typical arrangement. The temperature was increased up to 450 °C at a ramping rate of 5 °C min −1 and kept there for 30 min in Ar atmosphere to obtain NiFe-Se/CFP [ 118 ]. Synthesis protocols involving ZIF compounds as metal precursors follow a similar scheme.…”

“…In a similar vein to sulfides, bimetallic and multimetallic selenides supported on carbons can generally achieve higher electrocatalytic efficiency during the OER process than monometallic selenides [ 114 , 117 , 118 , 122 , 126 , 182 , 193 , 194 ]. A mixed NiFe selenide supported by carbon fiber paper (NiFe-Se/CFP) required an overpotential of 281 mV at 10 mA cm −2 in alkaline media (1 M KOH), whereas such a value for FeSe 2 /CFP was 395 mV [ 118 ]. An enhanced electron-transfer kinetics was observed for NiFe-Se/CFP with a Tafel slope of 41 mV dec −1 (42 mV dec −1 lower than for FeSe 2 /CFP).…”

“…Furthermore, the carbon-supported bimetallic chalcogenide catalyst has been proven to show good stability during the long-term (20 h) OER process. The post-test characterization of the NiFe-Se/CFP test suggests that the surface of the NiFe-Se nanoparticles undergoes a phase transformation from a bimetallic selenide phase to a mixed metal hydroxide/(oxy)hydroxide [ 118 ]. To understand the synergistic coupling between individual Co and Ni selenides, Liu et al designed a hybrid catalyst consisting of heterostructured CoSe 2 /Ni 3 Se 4 bimetallic selenides, N-doped carbon nanosheets, and Ketjen black carbon (CoSe 2 /Ni 3 Se 4 @NC/KB) [ 114 ].…”