Synthesis of Iron–Nickel Sulfide Porous Nanosheets via a Chemical Etching/Anion Exchange Method for Efficient Oxygen Evolution Reaction in Alkaline Media

Abstract

and so on. Among them, Ni-based materials, especially Ni 3 S 2 , have been extensively studied for use as an effective OER catalyst owing to its inherent advantages of good conductivity and unique 3D configuration. However, widespread use of Ni 3 S 2 electrocatalysts is still severely restricted by their low surface area exposure and poor electrocatalytic stability. [24,25] To overcome the above issues, it is vital to design efficient strategies to optimize the catalytic performances of the electrocatalysts. Most recently, Prussian blue analogs (PBAs) have been intensively employed for the applications in electrocatalysis, batteries and supercapacitors. [26][27][28] PBAs are considered as a promising class of materials because of 1) the 3D open framework with large interstitial sites; 2) the open, low strain, and tunable skeleton; 3) their adjustable composition, good structure, and chemical stability; and 4) their special thermal properties and unique reactivity. [26][27][28] When PBAs are applied for electrocatalysis, the porous PBA-derived materials with open diffusion channels, well-defined structure, and large surface area could be synthesized by taking PBAs as templates or precursors, such as transition metal sulfides, [29][30][31][32] selenides, [33] phosphides, [34,35] nitrides, [36] and oxides. [37] The specific structure of these porous PBA-derived materials is essential in providing rapid electron and electrolyte transportation pathway and improving the electrochemical properties.However, porous iron-nickel sulfide nanosheets derived from nickel-iron PBA (NiFe PBA) and nickel hydroxide have never been reported. Therefore, a simple and convenient approach should be developed to fabricate porous ironnickel sulfide nanosheets based on PBA. Inspired by these points, we successfully synthesized an interpenetrated porous 3D-networked FeS-Ni 3 S 2 on nickel foam (NF) through partial chemical etching of Ni(OH) 2 /NF nanosheets with Fe(CN) 6 3− to obtain Ni(OH) 2 @NiFe PBA/NF nanoarrays and subsequently treated with chemical etching/anion exchanging of Fe(CN) 6 3− and OH − by S 2− . [30,32,34] Benefiting from the unique interpenetrated porous 3D-networked architecture, the obtained metal sulfide electrode would expose large edge active sites and possess high-speed charge/mass transfer and relatively high electrochemical active area, resulting in the boosted electrocatalytic activities and durability for OER. [38] As a result, it delivers much The development of high-efficient and cost-effective catalytic electrodes for oxygen evolution reaction (OER) is highly desirable. Herein, interpenetrated porous 3D-networked iron-nickel sulfide nanosheets are synthesized on nickel foam (NF) (donated as FeS-Ni 3 S 2 /NF) via partial chemical etching of Ni(OH) 2 /NF precursor with Fe(CN) 6 3− , followed by chemical etching/anion exchanging of Fe(CN) 6 3− and OH − with S 2− . The resulting FeS-Ni 3 S 2 /NF nanosheets possess a remarkable catalytic activity for the OER with overpotentials of only 238 and 290 mV at 10 and 100 ...

Three‐Dimensional Electrodes for Oxygen Electrocatalysis

“…Therefore, the two components synergistically improved the overall OER performance (Figure 11 e and f). Jiang and co-workers [98] prepared iron-nickel sulfide nanosheets (FeS-Ni 3 S 2 /NF) with interpenetrated porous 3D-networks through a partial chemical etching reaction. Physical characterization showed that the unique interpenetrating porous 3D network structure exposed large active sites and effectively improved the proton transfer and charge transport.…”

Surface Fluorination Engineering of NiFe Prussian Blue Analogue Derivatives for Highly Efficient Oxygen Evolution Reaction

“…Prussian blue analogues (PBAs) with open frameworks are a class of metal–organic framework family, which contain transition metals (TMs) orderly coordinated with the ligands of the cyan group (CN – ). , The diversity of TM ions enables PBAs with easily tunable physicochemical properties and endows them with the potential applications for OER. , At present, PBAs have been widely utilized as the powerful precursors for the synthesis of various nanomaterials, such as nitrides, sulfides, , brides, phosphides, − and oxides. , However, the pyrolysis at high temperatures leads to the sharp collapse of the framework structures of PBAs on account of the uncontrolled removal of the CN – ligand, which induces a serious aggregation of their derivatives and cannot make full use of the structural advantages of PBAs . Additionally, the current research based on PBA derivatives mainly focus on the powder state, whereas the PBAs with multilevel nanostructures directly grown on metal substrates can expose more active sites and facilitate the charge-transfer process .…”

3D Cross-Linked Structure of Manganese Nickel Phosphide Ultrathin Nanosheets: Electronic Structure Optimization for Efficient Bifunctional Electrocatalysts

“…After long-term exploration by researchers, numerous non-noble metal-based electrocatalysts have been reported in recent years, especially transition-metal-based catalysts, for example, transition-metal alloys, , oxides, , sulfides, , phosphides, , and so forth. Among these, transition-metal phosphides were widely concerned relying on their unique electronic structure and catalytic effect, regarded as a kind of promising non-noble metal catalysts. , Plentiful monometallic phosphides, such as FeP, CoP, and Ni 2 P, have been already investigated and used as catalysts in the electrochemical field, showing pretty good electrocatalytic performance.…”

“…Exploiting high-efficiency and low-cost multifunctional electrocatalysts is still imperative as well as challenging. 10,11 After long-term exploration by researchers, numerous nonnoble metal-based electrocatalysts have been reported in recent years, especially transition-metal-based catalysts, for example, transition-metal alloys, 12,13 oxides, 14,15 sulfides, 16,17 phosphides, 18,19 and so forth. Among these, transition-metal phosphides were widely concerned relying on their unique electronic structure and catalytic effect, regarded as a kind of promising non-noble metal catalysts.…”