Surficial Reconstruction of Pt–Ni/NiS and Its Effect on Electrocatalytic Hydrogen Evolution in Alkaline Medium

Citations Over Time

Abstract

Cyclic voltammetry pretreatment of Pt-based electrocatalysts has been proven to be a normal activation process on achieving the optimal alkaline hydrogen evolution performance. Until now, the congruent relationship between the microstructural evolution and performance improvement during this process has rarely been reported. Herein, when the in situ transmission electron microscopy and in situ Raman analyses are employed, a self-reconstruction process from crystalline NiS into amorphous nickel hydroxide hydrate [Ni(OH)_2-x·H₂O, where x ≈ 0.3] on the surface of platinum-nickel nanowires has first been captured, which is the critical water dissociation active site to offer a sufficient proton supply. Furthermore, such a surficial reconstruction triggers an increase in the current density from -2.3 to -38.8 mA/cm2 (at -70 mV), which is nearly 17 times. These observations point to the fact that it is essential to consider the fundamental mechanisms of hydrogen evolution on the active sites when the process is scaled up.

Related Papers

• → The role of collisions in the aligned growth of vertical nanowires(2008)31 cited
• → A Study of Surface Oxides on Platinum Electrodes(1964)48 cited
• → Correlations of platinum-195-phosphorus-31 coupling constants with platinum-ligand and platinum-platinum bond lengths in platinum(I) dimers and in related platinum(II) complexes(1986)26 cited
• Absorption of light in InP nanowire arrays(2014)