Edge promotion and basal plane activation of MoS2 catalyst by isolated Co atoms for hydrodesulfurization and hydrodenitrogenation

Recent advances in defect-engineered molybdenum sulfides for catalytic applications

Electrochemical energy conversion and storage driven by renewable energy sources is drawing ever-increasing interest owing to the needs of sustainable development. Progress in the related electrochemical reactions relies on highly active and cost-effective catalysts to accelerate the sluggish kinetics. A substantial number of catalysts have been exploited recently, thanks to the advances in materials science and engineering. In particular, molybdenum sulfide (MoSx) furnishes a classic platform for studying catalytic mechanisms, improving catalytic performance and developing novel catalytic reactions. Herein, the recent theoretical and experimental progress of defective MoSx for catalytic applications is reviewed. This article begins with a brief description of the structure and basic catalytic applications of MoS2. The employment of defective two-dimensional and non-two-dimensional MoSx catalysts in the hydrogen evolution reaction (HER) is then reviewed, with a focus on the combination of theoretical and experimental tools for the rational design of defects and understanding of the reaction mechanisms. Afterward, the applications of defective MoSx as catalysts for the N2 reduction reaction, the CO2 reduction reaction, metal-sulfur batteries, metal-oxygen/air batteries, and the industrial hydrodesulfurization reaction are discussed, with a special emphasis on the synergy of multiple defects in achieving performance breakthroughs. Finally, the perspectives on the challenges and opportunities of defective MoSx for catalysis are presented.

Controlling basal plane sulfur vacancy in water splitting MoSx/NiF electrocatalysts through electric-field-assisted pulsed laser ablation

Eco-friendly, efficient, and durable electrocatalysts from earth-abundant materials are crucial for water splitting through hydrogen and oxygen generation. However, available methods to fabricate electrocatalysts are either hazardous and time-consuming or require expensive equipment, hindering the large-scale, eco-friendly production of artificial fuels. Here, we present a rapid, single-step method for producing MoSx/NiF electrocatalysts with controlled sulfur-vacancies via electric-field-assisted pulsed laser ablation (EF-PLA) in liquid and in-situ deposition on nickel foam, enabling efficient water splitting. Electric-field parameters efficiently control S-vacancy active sites in electrocatalysts. Higher electric fields yield a MoSx/NiF electrocatalyst with a larger density of S-vacancy sites, suited for HER due to lower Gibbs free energy for H∗ adsorption, while lower electric fields produce an electrocatalyst with lower S-vacancy sites, better suited for OER, as shown by both experimental and theoretical results. The present work opens a horizon in designing high-efficiency catalysts, for a wide range of chemical reactions.