Nanosheet-assembled MoSe₂ and S-doped MoSe_2−x nanostructures for superior lithium storage properties and hydrogen evolution reactions

Abstract

The development of layered molybdenum chalcogenides with largely exposed active sites is receiving intense interest because of their potential applications in energy storage and catalysis.

Interlayer Nanoarchitectonics of Two‐Dimensional Transition‐Metal Dichalcogenides Nanosheets for Energy Storage and Conversion Applications

“…Thus, it would be possible to achieve a thermoneutral state (Δ G H ≈ 0) by designing ternary alloyed MoS 2 x Se 2(1− x ) nanosheets with an optimized S/Se ratio. Improved HER activity has been experimentally demonstrated in S‐doped MoSe 2 nanosheets . Li et al reported a solvothermal route to synthesize a series of MoS 2 x Se 2(1− x ) nanosheets with tunable chalcogen composition.…”

Three‐Dimensional Architectures Constructed from Transition‐Metal Dichalcogenide Nanomaterials for Electrochemical Energy Storage and Conversion

“…As a result, large numbers of accessible active sites can be achieved for surface charge storage, fast kinetics, and rapid relax of structural strain induced by the Li insertion . Various TMDs with hollow structures have been synthesized and then used as anode materials for LIBs, including MoS 2 microboxes, C@MoS 2 nanoboxes, MoS 2 tubular structures, MoS 2 /C microspheres, MoS 2 hollow nanospheres, MoS 2 yolk‐shell structures, and MoSe 2− x nanotubes . Recently, Lou and co‐workers compared the electrochemical performance of the hollow MoS 2 microbox and solid MoS 2 microparticle, and found that the hierarchical MoS 2 microbox exhibited stable cycling performance and a high discharge capacity of 900 mAh g −1 after 50 cycles at a current density of 100 mA g −1 .…”

“…Thus, it is challenging to controllably synthesize edge‐terminated TMD structures. The construction of hierarchical 3D TMD architectures is an alternative to address this issue, since more edge sites can be exposed . For example, 3D MoS 2 nanoflowers with a high specific surface area of 431.2 m 2 g −1 exhibited an improved HER activity with an onset potential of 100 mV and a Tafel slope of 80.5 mV dec −1…”

Fabrication of Robust Hydrogen Evolution Reaction Electrocatalyst Using Ag2Se by Vacuum Evaporation

“…A pure 200 nm-thick Ag film (labeled as Ag) exhibited 588 mV at 10 mA·cm −2 , as shown in Figure 5a. In earlier studies, HER properties were demonstrated for the various layer materials including, bulk and their exfoliated layers of TMD materials such as high-quality monolayer MoS 2(1−x) Se 2x (η 10 mA·cm −2 = 273–300 mV) [19], S-doped MoSe 2−x nanotubes and MoSe 2 nanocaterpillars (η 2 mA·cm −2 = 95–318 mV) [20], tungsten selenide thin films deposited on tungsten foils (η 10 mA·cm −2 = 350 mV) [21], electrodeposition of amorphous cobalt–cobalt oxide/cobalt selenide (CoO x –CoSe) composite film on a 3-dimensional porous Ni foam (NF) (η 10 mA·cm −2 = 300–380 mV) [22], and electrodeposited cobalt selenide nanostructures (η 10 mA·cm −2 = 472–481 mV) [23].…”