Low-temperature one-pot synthesis of WS₂ nanoflakes as electrocatalyst for hydrogen evolution reaction

Abstract

Transition metal dichalcogenides have unique physicochemical properties. Herein, a lowtemperature facile method is demonstrated to synthesize ultrathin tungsten disulfide nanoflakes. They are loosely stacked between layers with highly exposed edges, which provide lots of active sites for electrochemical applications. The by-product of crystalline carbon improves their conductivity, which also enhances their performance in hydrogen evolution reaction.

Novel WS2-Based 3D Electrode with Protecting Scaffold for Efficient and Stable Hydrogen Evolution

“…The mass activity of this electrode at 300 mV was about 10 A•g −1 (normalized by the active loading weight), close to that of WS 2 nanoflakes reported recently. 37 The hydrogen evolution dynamics of the various samples was evaluated by the corresponding Tafel plots, as depicted in Figure 1b. The Tafel slope of the WS 2 /GR electrode was 47.9 mV•dec −1 , which was very close to that of the Pt electrode (38.3 mV•dec −1 ) and much superior to that of WS 2 -GC (84.2 mV•dec −1 ).…”

Photosensitive WS2/ZnO Nano-Heterostructure-Based Electrocatalysts for Hydrogen Evolution Reaction

“…Because of their controlled morphologies and atomically smaller size, they offer great catalytic activity even for their small amounts. 1,2,22 Additionally, the TMO/TMDC heterostructures/composites or TM/TMDCs heterostructures have shown great promise in the field of optoelectronics and selfdriven photodetectors because of the formation of the type-II junction at the interface. 23−25 High-performance devices can be fabricated using these heterostructures as they show high and stable photo-absorption over a broad range of the solar spectrum from ultraviolet to near infrared.…”

“…Two-dimensional transition-metal dichalcogenides (2D-TMDCs) have captivated tremendous attention because of their excessive capabilities toward the production of clean energy via electrochemical water splitting, , photocatalysis, and photovoltaic activities. , Particularly, transition-metal (TM) disulfides such as WS 2 , and MoS 2 − have been explored as catalysts for efficient and sustainable hydrogen evolution reactions (HERs) owing to excellent environmental and chemical inertness for prolonged time intervals. Huge amendments in the electrochemical activities have been demonstrated by various modifications in the chemical and physical properties .…”

“…Besides this, the synthesis of nanocomposites, nano-heterostructure, or nanohybrids has been proven to be more promising in the current scenario because of significant improvement in the HER activity by the highly controlled synthesis of catalysts with the desired proportion of materials and without disturbing the structural properties of host materials. , The use of various materials in the synthesis of nanocomposites, including nanostructures of transition-metal oxide (TMO) and noble metals, has shown enormous development in order to find the suitable catalyst with a low overpotential and high hydrogen yield. ,, Particularly, nanocomposites based on TMDCs, TMs, and TMOs have also emerged as high-performance catalysts ,, because of the simple and cost-effective synthesis and low hazard. Because of their controlled morphologies and atomically smaller size, they offer great catalytic activity even for their small amounts. ,, Additionally, the TMO/TMDC heterostructures/composites or TM/TMDCs heterostructures have shown great promise in the field of optoelectronics and self-driven photodetectors because of the formation of the type-II junction at the interface. − High-performance devices can be fabricated using these heterostructures as they show high and stable photo-absorption over a broad range of the solar spectrum from ultraviolet to near infrared. − These important optoelectronic ingredients of heterostructures can be utilized for the efficient photocatalysis. , Even, organic–inorganic nano-heterostructures can show a promising photoresponse owing to strong interface formation, which can be tuned by the proportion of constituents. − …”

Electrophoretic Deposition of MoSe2–MoOx Nanosheets for Enhanced Electrocatalytic Hydrogen Evolution Reaction

“…Of many non-noble-metal HER electrocatalysts, transition-metal dichalcogenides, − transition-metal oxides/hydroxides, − black phosphorous, carbon-based materials (i.e., carbon nanotubes, graphene, graphene oxide, and carbon nanostructures), conducting polymers such as polypyrrole and polyaniline, − and so forth stand out as the traditionally striking HER electrochemical catalysts. Two-dimensional transition-metal dichalcogenides (2D-TMDCs) including MoS 2 , − WS 2 , MoSe 2 , and WSe 2 have gained huge attention owing to their tunable catalytic activities. Normally, 2D-TMDCs have demonstrated poor electrocatalytic HER as their basal planes are inactive toward electrocatalysis. ,− Edges of 2D-TMDCs are active owing to the strained atomic sites .…”