Engineering the Electronic Structure of 2D WS2 Nanosheets Using Co Incorporation as CoxW(1-x)S2 for Conspicuously Enhanced Hydrogen Generation

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• 作者：Tofik Ahmed Shifa ; Fengmei Wang ; Kaili Liu ; Kai Xu ; Zhenxing Wang ; Xueying Zhan ; Chao Jiang and Jun He
• 刊名：Small
• 出版年：2016
• 出版时间：July 27, 2016
• 年：2016
• 卷：12
• 期：28
• 页码：3802-3809
• 全文大小：2190K
• ISSN：1613-6829

文摘

Transition metal dichalcogenides (TMDs), as one of potential electrocatalysts for hydrogen evolution reaction (HER), have been extensively studied. Such TMD-based ternary materials are believed to engender optimization of hydrogen adsorption free energy to thermoneutral value. Theoretically, cobalt is predicted to actively promote the catalytic activity of WS₂. However, experimentally it requires systematic approach to form Co_xW_(1−x)S₂ without any concomitant side phases that are detrimental for the intended purpose. This study reports a rational method to synthesize pure ternary Co_xW_(1−x)S₂ nanosheets for efficiently catalyzing HER. Benefiting from the modification in the electronic structure, the resultant material requires overpotential of 121 mV versus reversible hydrogen electrode (RHE) to achieve current density of 10 mA cm⁻² and shows Tafel slope of 67 mV dec⁻¹. Furthermore, negligible loss of activity is observed over continues electrolysis of up to 2 h demonstrating its fair stability. The finding provides noticeable experimental support for other computational reports and paves the way for further works in the area of HER catalysis based on ternary materials.