Recent Advances in Defect-Engineered Transition Metal Dichalcogenides for Enhanced Electrocatalytic Hydrogen Evolution: Perfecting Imperfections

Abstract

Switching to renewable, carbon-neutral sources of energy is urgent and critical for climate change mitigation. Despite how hydrogen production by electrolyzing water can enable renewable energy storage, current technologies unfortunately require rare and expensive platinum group metal electrocatalysts, which limit their economic viability. Transition metal dichalcogenides (TMDs) are low-cost, earth-abundant materials that possess the potential to replace platinum as the hydrogen evolution catalyst for water electrolysis, but so far, pristine TMDs are plagued by poor catalytic performances. Defect engineering is an attractive approach to enhance the catalytic efficiency of TMDs and is not subjected to the limitations of other approaches like phase engineering and surface structure engineering. In this minireview, we discuss the recent progress made in defect-engineered TMDs as efficient, robust, and low-cost catalysts for water splitting. The roles of chalcogen atomic defects in engineering TMDs for improvements to the hydrogen evolution reaction (HER) are summarized. Finally, we highlight our perspectives on the challenges and opportunities of defect engineering in TMDs for electrocatalytic water splitting. We hope to provide inspirations for designing the state-of-the-art catalysts for future breakthroughs in the electrocatalytic HER.

Transforming the Petroleum Industry through Catalytic Oxidation Reactions vis-à-vis Preceramic Polymer Catalyst Supports

“…262 Water splitting, methane oxidation, and methanol synthesis are all part of a wider conversion to fuel cycle that involves the evolution of oxygen, carbon monoxide, and hydrogen as one component as well as the formation of a reduced fuel as a final product. 263,264 Complete conversion is a multielectron process that benefits from catalysts like preceramic polymer-based catalysts. 197 Capture, conversion, and storage are all required for alternative fuel production via oxidative processes.…”

In Situ Growth of Interfacially Nanoengineered 2D–2D WS2/Ti3C2Tx MXene for the Enhanced Performance of Hydrogen Evolution Reactions

“…10 However, the inactive basal planes in 2D TMDs sometimes limit their performance. 11,12 Construction of a 2D−2D heterostructure and interfacial engineering can enhance the charge mobility and reductive behavior at the active sites, which provides faster kinetics for electrocatalysis with higher efficiency and durability. 13,14 2D−2D heterostructure formation can cause the formation of dissimilar atomic layers with strong covalent bonds that will energize the inert basal plane in single 2D layers and enhance sufficient in-plane stability.…”

“…MXene, a 2D multilayered material, has excellent conductivity (∼6500 S cm –1 ) and can serve as a good conducting support material for the uniform growth of 2D dichalcogenide sheets over and in-between the layers to obtain a sandwiched wafer-like continuum for enhanced charge transfer and active sites . However, the inactive basal planes in 2D TMDs sometimes limit their performance. , Construction of a 2D–2D heterostructure and interfacial engineering can enhance the charge mobility and reductive behavior at the active sites, which provides faster kinetics for electrocatalysis with higher efficiency and durability. , …”

Preparation of Cu(OH)2/Cu2S arrays for enhanced hydrogen evolution reaction

“…Moreover, the strong binding energy of the metal-sulfur bond enhances hydrogen atom binding during electrochemical testing, effectively promoting the reaction kinetics of the Volmer step and improving catalytic activity. [38][39][40] Zhang et al prepared Cu 9 S 5 @MoS 2 /CNFs core-shell nanocrystals using electrospinning and chemical vapor deposition techniques. By adjusting the mass ratio of Cu and Mo precursors, the researchers discovered that a 3:1 ratio produced Cu 9 S 5 @MoS 2 /CNFs with the least amount of MoS 2 shells, resulting in optimal HER performance at a current density of 10 mA cm −2 .…”

“…The abundance of electron holes on the sulfur orbital enables smoother interaction between Cu x S and electrons, thereby facilitating electron transfer during the reaction process. Moreover, the strong binding energy of the metal–sulfur bond enhances hydrogen atom binding during electrochemical testing, effectively promoting the reaction kinetics of the Volmer step and improving catalytic activity 38–40 . Zhang et al prepared Cu 9 S 5 @MoS 2 /CNFs core–shell nanocrystals using electrospinning and chemical vapor deposition techniques.…”