A Novel Metal–Organic Framework Intermediated Synthesis of Heterogeneous CoS₂/CoS Porous Nanosheets for Enhanced Oxygen Evolution Reaction

Abstract

Designing and constructing transition metal sulfides (TMSs) as oxygen evolution reaction (OER) electrocatalysts has been attracting increasing attention. Interface engineering can effectively modify the active sites and promote electron transfer, resulting in improvement of electrocatalytic performance. Here, freestanding heterogeneous CoS2/CoS nanosheets are prepared via a simple one‐step sintering process from a kind of novel hierarchical tremella‐like metal–organic framework (MOF). The formation mechanism of the unique MOF and the heterojunctions between CoS2 and CoS is analyzed. Consequently, the prepared cost‐effective OER electrocatalyst achieves satisfying electrocatalytic efficiencies with a diminutive overpotential of 269 mV at 10 mA cm−2 current density, a small Tafel slope of 52 mV dec−1, and good stability in alkaline solution comparable to RuO2 counterparts. This work opens up a new method for constructing 2D electrocatalysts containing catalytic interfaces with boosted OER performance.

Facile Fabrication of Iron Cobalt Sulfide Nanoparticles within N-Doped Graphene for High-Performance Supercapacitors

“…The deconvoluted Co 2p in Figure b depicts the Co 2p 3/2 located at 782.4 eV and Co 2p 1/2 located at 798.5 eV. The Co 2p 3/2 and Co 2p 1/2 are divided into two separating peaks, attributed to the Co 2+ and Co 3+ oxidation states, respectively, while the peaks at 785.6 and 803.2 eV are assigned to the satellite peak of Co 2+ . , The high-resolution Fe 2p spectrum as displayed in Figure c is separated into two doublets at 711.6 and 724.2 eV, corresponding to Fe 2p 3/2 and Fe 2p 1/2 , respectively . The characteristic peaks of Fe 2p 3/2 and Fe 2p 1/2 are ascribed to the different valences of Fe 2+ and Fe 3+ .…”

Cobalt sulfide films by sulfurizing cobalt for resistive switching memory

“…89-3056). 23) According to the Raman and XRD analyses, the CoS x film formed on top of the Co film has mixed phases of Co 9 S 8 and CoS 2 . To further analyze the structure of CoS x films, HRTEM was performed and the resulting image is shown in Fig.…”

Effect of Interfacial Strength and Anchoring in a Highly Efficient NiTe2/NF@CuFe Oxygen-Evolution Catalyst

“…It should be noted that the NiTe 2 /NF@CuFe catalyst exhibited the lowest Tafel slope of 33 mV dec –1 (Figure c), which is clearly lower than those of NiTe 2 /NF@Cu (149 mV dec –1 ), NiTe 2 /NF@Fe (45 mV dec –1 ), and NiTe 2 /NF (114 mV dec –1 ). The OER activities of most reported electrocatalysts and NiTe 2 /NF@CuFe catalyst at 10 mA cm –2 are shown in Figure d and summarized in Table S2. − Clearly, the NiTe 2 /NF@CuFe catalyst exhibits robust OER activity in 1.0 M KOH.…”