Highly Dispersible Hexagonal Carbon–MoS₂–Carbon Nanoplates with Hollow Sandwich Structures for Supercapacitors

Abstract

MoS2, a typical layered transition‐metal dichalcogenide, is promising as an electrode material in supercapacitors. However, its low electrical conductivity could lead to limited capacitance if applied in electrochemical devices. Herein, a new nanostructure composed of hollow carbon–MoS2–carbon was successfully synthesized through an l‐cysteine‐assisted hydrothermal method by using gibbsite as a template and polydopamine as a carbon precursor. After calcination and etching of the gibbsite template, uniform hollow platelets, which were made of a sandwich‐like assembly of partial graphitic carbon and two‐dimensional layered MoS2 flakes, were obtained. The platelets showed excellent dispersibility and stability in water, and good electrical conductivity due to carbon provided by the calcination of polydopamine coatings. The hollow nanoplate morphology of the material provided a high specific surface area of 543 m2 g−1, a total pore volume of 0.677 cm3 g−1, and fairly small mesopores (≈5.3 nm). The material was applied in a symmetric supercapacitor and exhibited a specific capacitance of 248 F g−1 (0.12 F cm−2) at a constant current density of 0.1 A g−1; thus suggesting that hollow carbon–MoS2–carbon nanoplates are promising candidate materials for supercapacitors.

Direct Synthesis of Microporous Bicarbazole‐Based Covalent Triazine Frameworks for High‐Performance Energy Storage and Carbon Dioxide Uptake

“…The precipitate was filtered off and dried under vacuum at 50°C to afford a white solid (3.6 g). 1 3,3',6,6'-Tetrabromo-9,9'-bicarbazole (Car-4Br) [39,40] In a 250-mL one-neck bottle, a solution of 3,6-dibromocarbazole (3.00 g, 9.23 mmol) and KMnO 4 (4.38 g, 27.9 mmol) in acetone (80 mL) was heated under reflux at 50°C for 6 h. Distilled water (50 mL) was added and then the mixture stirred for 2 h at 25°C. The aqueous phase was extracted three times with DCM (50 mL).…”

“…The combined organic phases were dried (anhydrous MgSO 4 ) and concentrated under reduced pressure to give a white powder (6.92 g). 1…”

“…Electric double-layer capacitors are energy storage devices (supercapacitors) that have received much attention from both academia and industry because of their excellent reversibility, high power densities, extra-long cycle lives, discharge/charge ability, and wide window of working temperatures. [1][2][3][4][5][6][7] With these outstanding properties, electric double-layer capacitors have been applied in energy storage devices, digital devices, electrical vehicles, and pulsing technologies. [8][9][10][11] The energy storage mechanism in supercapacitors depends mainly on the nature of the electrode material; it can be achieved through either Faradaic or non-Faradaic processes.…”

A Facile Grinding Method for the Synthesis of 3D Ag Metal–Organic Frameworks (MOFs) Containing Ag6Mo7O24 for High‐Performance Supercapacitors

“…[7,8,9] The electrode materials are the main factor affecting the performance of SCs. In particular, pseudo-capacitor electrode materials can fall into three types:c arbon, [10] conductive polymers, [11][12][13] and metal oxides, [14,15] hydroxide, sulfides, [16] and their composites. [17,18] However,o wing to the redoxr eaction, these materials can undergo mechanical changes,s ot hey usu-ally show poor mechanical stability and then the electrode is not ablet oe xpand or shrink.…”

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

“…[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.…”