Ultra-thin MoSx film for electrochemical hydrogen production: Correlation between the catalytic activities and electrochemical features

The correlation between the catalytic activities and electrochemical features of MoSx material is important to study the work process of structure on catalytic performance. In this work, adopting the centimeter-scale ultra-thin MoSx film as a research model, we try to establish a persuasive electrochemical features–catalysis correlation in two different ultra-thin MoSx structures, of which one is O contaminated and another is O free. The results indicate that whatever the structure of MoSx is, high turnover frequency (TOF) and large cathodic current density (J) require low charge-transfer resistance (Rct); low over-potential (η) requires low charge-transfer resistance (Rct) and rich active sites; low Tafel slope requires the high activity of the active sites; and high exchange current densities (Jo) requires a match between the activity of the active sites and Rct. These results provide useful information for the further improvement of MoSx material. From the catalytic activities we can infer which parameters of the electrochemical features need to be improved, and then selectively adjust its physical structure.