A Zinc Cobalt Sulfide Nanosheet Array Derived from a 2D Bimetallic Metal–Organic Frameworks for High‐Performance Supercapacitors

Abstract

Porous ternary metal sulfide integrated electrode materials with abundant electroactive sites and redox reactions are very promising for supercapacitors. Herein, a porous zinc cobalt sulfide nanosheet array on Ni foam (Zn-Co-S/NF) was constructed by facile growth of 2D bimetallic zinc/cobalt-based metal-organic framework (Zn/Co-MOF) nanosheets with leaf-like morphology on NF, followed by additional sulfurization. The Zn-Co-S/NF nanosheet array acted directly as a supercapacitor electrode showing much better electrochemical performance (2354.3 F g and 88.6 % retention over 1000 cycles) when compared with zinc cobalt sulfide powder (355.3 F g and 75.8 % retention over 1000 cycles), which originates from good electrical conductivity and mechanical stability, abundant electroactive sites, and facilitated transportation of electrons and electrolyte ions due to the unique nanosheet array structure. An asymmetric supercapacitor (ASC) device assembled from Zn-Co-S/NF and activated carbon electrodes can deliver a highest energy density of 31.9 Wh kg and a maximum power density of 8.5 kW kg . Most importantly, this ASC also shows good cycling stability (71.0 % retention over 10000 cycles). Furthermore, a red LED can be powered by two connected ASCs, and thus as-synthesized Zn-Co-S/NF has great potential for practical applications.

Structural Engineering of Low‐Dimensional Metal–Organic Frameworks: Synthesis, Properties, and Applications

“…[258] Besides, multistep pretreatments before calcination, such as anion exchange and etching, can obtain MOF derivatives with more complex composition and/or structure. [260] Recently, a novel one-step and energy-saving method was proposed to synthesize 2D MOF-derivatives. [259] Furthermore, 2D MOF-derivatives can be also obtained through hydrothermal/ solvothermal reaction.…”

“…[61] For example, Wang and co-workers reported a two-step strategy, i.e., ion exchange and etching process followed by thermal treatment in air, to prepare hollow NiCo 2 O 4 nanowall arrays on carbon cloth. [260] A porous zinc cobalt sulfide nanosheet array grown on Ni foam was prepared in a simple sulfurization reaction with thioacetamide, which was based on the sacrificial template of 2D Zn/Co-MOF nanosheets.…”

Vanadium‐Incorporated Metallic (1‐T) Molybdenum Sulfide Nanoroses for High‐Energy‐Density Asymmetric Supercapacitors

“…Particularly, bimetallic sulfides have tremendous potential to compensate the electrochemical limitations posed by single‐metal sulfides . Sahoo et al.…”

“…[14] Particularly,b imetallic sulfides have tremendous potential to compensate the electrochemical limitations posed by single-metal sulfides. [15,16] Sahoo et al aimed to investigate the electrochemical properties of Cu 2 MoS 4 on Ni foam to achieve a high-energy-density supercapacitor. [17] However,E lkholye tal.…”

An Eco‐Friendly Nitrogen Source for the Preparation of Vanadium Nitride/Nitrogen‐Doped Carbon Nanocomposites for Supercapacitors

“…[9] On the other hand, pseudo-capacitive materials, such as transition metal oxides/hydroxides/sulfides and conducting polymers, usually show a much higher specific capacitance than that of carbon-based materials due to the fast redox reactions. [10][11][12][13][14] However, their low electrical conductivity always results in a low power density. [15] Thus, it is anticipated that hybridizing pseudo-capacitive materials with carbon-based materials might be a promising strategy for attaining a high energy and power density of SCs simultaneously.…”