【作者】 汪浩； 汤浩然； 李永新；

【Author】 Hao Wang;Haoran Tang;Yongxin Li;Anhui Normal University;

【机构】 安徽师范大学化材学院；

【摘要】 研究单个纳米粒子（NPs）与电极的碰撞可以提供对其电催化行为,质量传输以及与表面相互作用的新见解。在这里,我们演示了一种单实体电化学方法,可帮助我们通过使用超微电极（UME）在单个二硫化钼（MoS₂）量子点（QDs）水平上研究其析氢反应（HER）活性。在银超微电极表面,MoS₂量子点碰撞的i-t响应由重复的电流"尖峰"组成,这些"尖峰"随着氢的形成并覆盖量子点表面而回到背景水平。相比之下,MoS₂量子点碰撞在碳超微电极表面时观察到逐步的"阶梯"i-t响应。结果还表明,银超微电极上单个MoS₂量子点碰撞的电流密度远高于碳超微电极,这揭示了金属-MoS₂界面对HER性能的独特特性,并通过热力学分析和密度泛函理论（DFT）进行了证明。计算发现,MoS₂量子点与基底电极之间的相互作用导致氢吸附能(E_ads)和吉布斯自由能（ΔG_H）发生显着变化,从而导致析氢反应活性的差异。更多还原

【Abstract】 It is still a challenge to identify the intrinsic electrocatalytic activity of single MoS₂ QD because their characterization usually dissects contributions from a large amount of particles.Herein we demonstrate a single entity electrochemical method to help us investigate the enhancing hydrogen evolution reaction（HER） activity at single MoS₂ QDs level by using silver ultramicroelectrodes（UMEs）.At Ag UMEs,the i-t response for MoS₂ QDs collision consists of repeated current "spikes" that return to the background level as hydrogen formation and covering QDs surface.In contrast,a stepwise "staircase" i-t response is observed for MoS₂ QDs colliding on carbon UMEs（C UMEs）.Results also show that the current density of single MoS₂ QDs collision on Ag UMEs is much higher than on C UMEs,revealing the unique property of metal-MoS₂ interface on HER performance,which has been demonstrated by thermodynamic analysis and density functional theory（DFT） calculations.It has been found that the interactions between MoS₂ QDs and substrate UMEs lead to significant changes in the hydrogen adsorption energies(ΔE_ads) and Gibbs free energy（ΔG_H）,resulting in the difference in HER activity.更多还原