Microwave synthesized dry leaf-like mesoporous MoSe2 nanostructure as an efficient catalyst for enhanced hydrogen evolution and supercapacitor applications

Manganese-cobalt hydroxide nanosheets anchored on a hollow sulfur-doped bimetallic MOF for high-performance supercapacitors and the hydrogen evolution reaction in alkaline media

Nonmetallic doping and in situ growth techniques for designing electrode materials with excellent electrocatalytic activity are effective strategies to enhance the electrochemical performance. Bifunctional electrode materials for supercapacitors (SCs) and the hydrogen evolution reaction (HER) have attracted great interest due to their potential applications in green energy storage and conversion. Herein, the bimetallic MnCo LDH is anchored on a hollow sulfur (S)-doped MnCo-MOF-74 surface, forming a poplar flower-like 3D composite which is used for SCs and the HER in alkaline media. The fabricated S-MnCo-MOF-74@MnCo LDH/NF electrode exhibits a favorable specific capacitance of 1875.4 F g-1 at 1 A g-1 and steady long-term cycling performance. Moreover, the assembled HSC using S-MnCo-MOF-7@MnCo LDH/NF as the cathode material and active carbon (AC) as the anode material shows 546.4 F g-1 capacitance (1 A g-1) with a maximum energy density of 58 W h kg-1 at 14 000 W kg-1 power density. As an electrocatalyst, S-MnCo-MOF-7@MnCo LDH/NF exhibits excellent HER properties with a small Tafel slope of 128.9 mV dec-1 a low overpotential of 197 mV at 10 mA cm-2 and durable performance for 10 hours in alkaline media. The present work provides insights into understanding and designing active electrode materials for stable hydrogen evolution and high-performing supercapacitors in an alkaline environment.

Facile Synthesis of Copper Oxide-Cobalt Oxide/Nitrogen-Doped Carbon (Cu2O-Co3O4/CN) Composite for Efficient Water Splitting

Herein, we report a copper oxide-cobalt oxide/nitrogen-doped carbon hybrid (Cu2O-Co3O4/CN) composite for electrochemical water splitting. Cu2O-Co3O4/CN is synthesized by an easy two-step reaction of melamine with Cu2O-Co3O4/CN composite. The designed composite is aimed to solve energy challenges by producing hydrogen and oxygen via electrochemical catalysis. The proposed composite offers some unique advantages in water splitting. Carbon imparts superior conductivity, while the water oxidation abilities of Cu2O and Co3O4 are considered to constitute a catalyst. The synthesized composite (Cu2O-Co3O4/CN) is characterized by SEM, EDS, FTIR, TEM, and AFM in terms of the size, morphology, shape, and elemental composition of the catalyst. The designed catalyst’s electrochemical performance is evaluated via linear sweep voltammetry (LSV) and cyclic voltammetry (CV). The Cu2O-Co3O4/CN composite shows significant electrocatalytic activity, which is further improved by introducing nitrogen doped carbon (current density 10 mA cm−2, onset potential 91 mV, and overpotential 396 mV).

Transition metal dichalcogenide (TMDs) electrodes for supercapacitors: a comprehensive review

As globally, the main focus of the researchers is to develop novel electrode materials that exhibit high energy and power density for efficient performance energy storage devices. This review covers the up-to-date progress achieved in transition metal dichalcogenides (TMDs) (e.g. MoS₂, WS₂, MoSe_2,and WSe₂) as electrode material for supercapacitors (SCs). The TMDs have remarkable properties like large surface area, high electrical conductivity with variable oxidation states. These properties enable the TMDs as the most promising candidates to store electrical energy via hybrid charge storage mechanisms. Consequently, this review article provides a detailed study of TMDs structure, properties, and evolution. The characteristics technique and electrochemical performances of all the efficient TMDs are highlighted meticulously. In brief, the present review article shines a light on the structural and electrochemical properties of TMD electrodes. Furthermore, the latest fabricated TMDs based symmetric/asymmetric SCs have also been reported.

Si Quantum Dots Assist Synthesized Microflower-Like Si/MoS2 Composites for Supercapacitors

The microflower-like Si/MoS2 composites were fabricated using Si quantum dots (QDs) to assist a facile hydrothermal method. The electrochemical performance of Si/MoS2 composite in symmetric and asymmetric systems was studied. Electrochemical characterization revealed that the Si/MoS2 composite electrode in a three-electrode system has a high specific capacitance of 574.4 F·g−1 at 5 A·g−1. Furthermore, the Si/MoS2 composite electrode in a two-electrode system had the maximum energy density of 27.2 Wh·kg−1 when a power density of 749.1 W·kg−1 was achieved. Therefore, this investigation proves the Si/MoS2 composite microflower-like structure should be a promising candidate electrode material for supercapacitors.