Role of cooperative effect by Mo and Pd mixed micellar assemblies for displaying the Pt/C like hydrogen evolution reaction

Abstract

Cooperative effect as well as interfacial engineering are crucial factors for the development of electrochemical hydrogen evolution reaction (HER). Keeping this aspect in mind, a novel mixed micellar film using dodecylamine molybdenum (III) trichloride (MoDDA(I)) and dodecylamine palladium (II) dichloride (PdDDA(I)) was fabricated for electrochemical HER. The mixed micellar film was characterized by various instrumentation techniques to explore its structure and composition i.e. FESEM, AFM, FTIR. In addition, XPS was inserted to understand the underlying mechanism before and after electrolysis. The fabricated surface of mixed micelles was found to be hydrophobic. The efficiency of mix-metallomicelles as an electrocatalyst was checked in acidic media for electrochemical HER. The prepared reverse micellar film was activated by polarization cycles due to the in-situ reduction of metallic components. These metallic cores act as active centers for electrocatalytic HER. The HER activity of Mo-PdDDA(I) was found to be superior as compared with Pt/C. The prepared mixed micelles displayed 29.2 mV dec−1 Tafel slope. First, Mo and Pd based mixed micelles were prepared using a one-pot method. Benefiting from the role of organic media, MoDDA(I) and PdDDA(I) were able to orient in the form of reverse micelles. Wherein, Mo and Pd metal ions are present in the core of the micelles. The excellent activity exhibited by the formation of mix-metallomicelles, a synergic effect between metal ions, and interfacial engineering introduced by the surfactant moiety, which in turn facilitates the adsorption and activation of hydrogen ions on the electrode surface. Additionally, the mixed micelles provide a high surface area for the electrochemical reaction and enhance the conductivity of the electrode.