Amorphous MoS2 coated Ni3S2 nanosheets as bifunctional electrocatalysts for high-efficiency overall water splitting

Deng

et al. 2021

Adv Materials Inter

precious metal-based electrocatalysts, such as platinum, iridium, or ruthenium, exhibit the outstanding catalytic performance, the costly price and scarcity confine their wide application. [6,7] Hence, it is compulsory to explore cost-effective, highly efficient, and long-life catalysts based on nonprecious metals. [8] Recently, transition metal-based electrocatalysts including transition-metal nitride, [9] phosphides, [10,11] and oxides [12] have been widely used for water splitting. Among them, transition metal sulfides included both layered MS 2 (such as MoS 2 , WS 2 ) and nonlayered M x S y (such as Co 9 S 8 , ZnS) are at the cutting edge owing to their structural diversity, electrical activity, and superior electrocatalytic performance. [13,14] Especially, molybdenum sulfide (MoS 2 ), which possesses 2D structure, stable physical, and chemical properties, has showed the superior HER activity in acidic and base media. [15] However, the HER performances of layered MoS 2 materials are still unable to overshine the Pt-based electrocatalysts because of poor conductivity and unexposed active sites. [1,16] To overcome these shortcomings, hybridizing MoS 2 with other active composites with high electrical conductivity to build heterostructure is a promising strategy, which exhibits synergistically promoted kinetics and tunes the electron configuration and possesses diverse active sites. [17] For instance, nickel sulfides (Ni x S y ) not only display good conductivity, but also are active for OER. [16,18] Many reports have illustrated that hybridizing two or more metal sulfides into a composite can significantly prompt the HER performance, even it provides a considerable solution to construct electrocatalysts for water splitting. [19,20] The promoted performance for such binary nanostructures could be primarily ascribed from modulated the electronic structure, their abundant reactive redox sites, synergistic interfaces, and customized conductivity. [21] For instance, Liu's group reported the yolk-shell MoS 2 /NiS-based materials for electrochemical water splitting only requiring a potential of 1.64 V in the base solution at 10 mA cm −2 . [22] Feng et al. constructed MoS 2 / Ni 3 S 2 nanocomposites on nickel foam generating ample interfaces. [23] Zhai et al. reported NiS 2 /CoS 2 /MoS 2 nanosheet arrays vertically grown on Ni foam by two facile procedures. [24] Nonetheless, the scarcity of inherent conductivity hinders these bifunctional nanohybrids to be the best replacement for precious-metal based electrocatalysts. [25] Consequently, structural construction and optimization linked to conductivity and performance are significant to attain advanced binary hybrids.

Section: Resultsmentioning

confidence: 97%

Building Ni₉S₈/MoS₂ Nanosheets Decorated NiMoO₄ Nanorods Heterostructure for Enhanced Water Splitting

Deng

et al. 2021

Adv Materials Inter

“…3 c, the binding energy signals at 163.6, 161.5 eV were allocated with the 2p 1/2 and 2p 3/2 of nickel-sulfur bonding, two signals at 163.5 and 161.6 eV were assigned to the molybdenum-sulfur bonding (2p 1/2 and 2p 3/2 ), respectively [ 42 , 46 ]. Also, a typical peak of the sulfur-oxygen bond with oxidation state appeared at signal 168.4 eV [ 47 ]. O1s spectrum is displayed as Fig.…”

Section: Resultsmentioning

confidence: 99%

Hetero-architectured core–shell NiMoO4@Ni9S8/MoS2 nanorods enabling high-performance supercapacitors

Deng

Journal of Materials Research

et al. 2021

An effective technique for improving electrochemical efficiency is to rationally design hierarchical nanostructures that completely optimize the advantages of single components and establish an interfacial effect between structures. In this study, core–shell NiMoO4@Ni9S8/MoS2 hetero-structured nanorods are prepared via a facile hydrothermal process followed by a direct sulfurization. The resulting hierarchical architecture with outer Ni9S8/MoS2 nanoflakes shell on the inner NiMoO4 core offers plentiful active sites and ample charge transfer pathways in continuous heterointerfaces. Ascribing to the porous core–shell configuration and synergistic effect of bimetal sulfides, the obtained NiMoO4@Ni9S8/MoS2 as electrode material presents an unsurpassed specific capacity of 373.4 F g−1 at 10 A g−1 and remarkable cycling performance in the 6 M KOH electrolyte. This work delivers a rational method for designing highly efficient electrodes for supercapacitors, enlightening the road of exploring low-cost materials in the energy storage domain. Graphical Abstract

“…Other [112], WS 2 supported on TiO 2 [113], N-doped reduced graphene oxide supported CoSe 2 [114], Co 9 S 8 supported on N,S co-doped carbon [115], MoNiS@NiS [116] [123]. Wu et al proposed interesting strategies for tuning the electrocatalytic performance of rGO-supported molybdenum phosphide, using NaCl as a solid template.…”

Section: Supported Chalcogenides Hydroxides Pnictides and Carbidesmentioning

confidence: 99%

Hydrogen Evolution Reaction-From Single Crystal to Single Atom Catalysts

et al. 2020

Hydrogen evolution reaction (HER) is one of the most important reactions in electrochemistry. This is not only because it is the simplest way to produce high purity hydrogen and the fact that it is the side reaction in many other technologies. HER actually shaped current electrochemistry because it was in focus of active research for so many years (and it still is). The number of catalysts investigated for HER is immense, and it is not possible to overview them all. In fact, it seems that the complexity of the field overcomes the complexity of HER. The aim of this review is to point out some of the latest developments in HER catalysis, current directions and some of the missing links between a single crystal, nanosized supported catalysts and recently emerging, single-atom catalysts for HER.